It has 4 but only 3 are available for games.

Thats not hole story, A76 can also clock more than A73. Zen 2 will maybe have 3x higher IPC than A76, but A76 is 2018. CPU, Switch will most likly using ARM CPU from 2021/2022.

Thats not true, A76 can already go to 3GHz. Switch has 20nm chipset, A76 is already making in 7nm, that means that Switch 2 will most likely have 7nm chipset at least, and there is huge difference betwine 20nm and 7nm only if we talk about same CPU or GPU, not mentioned next gen and improved CPU/GPU with 7nm. So yeah, Switch 2 will most likely have more CPU and GPU cores than current Switch has, with higher clocks also.

2015. tech architecture vs 2012. tech architecture. ARM is most used CPU in world, most popular tech device (smart phone) on world in most cases works on ARM CPUs, mobile CPUs have much more space for growth than any other CPU.

No 2020 or 2021.

Goes without saying that the Switch 2 will have a stronger CPU.
But Ryzen is in another league entirely to ARM's offerings.

And just because ARM has an A76 core on the market, doesn't mean  the Switch 2 is going to use it... Why? Because nVidia might build another SoC that is based around Denver.

Still won't hold a candle to Ryzen.

Just because it can clock higher, doesn't mean it will.
Nintendo may have a preference in downclocking the CPU in order to bolster the GPU side of the equation, mobile devices need to keep power consumption check, doubly so for one that is dedicated to gaming.

Either way... Don't see 3Ghz being the norm for ARM chips anytime soon, ARM's claims of 3ghz chips before have never really materialized.

More impressive relative to their hardware, or in terms of subjective aesthetics perhaps, but even PS3/360's best looking games are objectively less technically advanced than Switch's, as their hardware is older and weaker.

It’s ok...keep living in the past, if you must.

Ryzen is another league, but Switch 2 will be most likely released 2-3 years after PS5/XB2, so must likely we will comparing newer ARM CPU compared than Ryzen in PS5/XB2.

Well that assumption, but with point that Nintendo already using ARM most likely they will stick to ARM with Switch 2 also. Nvidia itself said they will have partnership with Nintendo that will last at least 20 years, we talking about very strong relationship, so it's very possible they will make custom SoC for Nintendo needs where Nintendo will choose what they want.

We dont know that, we dont know how strong ARM CPUs will be in few years. Like I wrote, I expecting in any case that PS5/XB2 CPU will again be stronger, but that Switch2 will have comparible CPU for its need, in this case that runs 4K PS5/XB2 games at 1080p at least in docked mode.

We can bet they will have higher clock than current 1GHz, Nintendo preferred lower clocks because they couldn't had higher currently, in this case we most likely talking 7nm vs 20nm if comparing Switch 2 and Switch.

Yes, 3GHz still didn't used for ARM CPUs in devices, but 2.5GHz is used, I dont see why will not see 3GHz also used in few years. Also even Switch uses 2GHz with much more modern and stronger CPU with more than 3 available cores for games, compared to current Switch CPU, we talking about huge difference in any case.

I think a setup that would work well for Nintendo is not necessarily going after hundreds of third party titles for a "Switch Pro" (hypothetical).

What you want is just to add some more appeal/breadth to the portable console concept, you don't need to get into a pissing match with Sony/MS, especially when you already have Nintendo's big IP.

I think you'd want to add a few franchise entries like Kingdom Hearts 3, Call of Duty (series), Grand Theft Auto V (w/online), Final Fantasy VII Remake, Resident Evil (main series), Assassin's Creed series (no streaming), Elder Scrolls VI, Star Wars Battlefront, Dark Souls III as Pro-only titles.

That's about it, it wouldn't necessarily be about suddenly competing for hundreds of titles. You just want to add a few of the bigger industry IP to increase the appeal of the unit.

I think Kingdom Hearts 3, Resident Evil 2 Remake, Call of Duty, and GTAV would all potentially be million+ sellers on the Switch which would make a port worthwhile. It's not about competing or getting the same numbers as what Sony/MS get, just expanding out the appeal of the ecosystem and I think there is certainly a market of people who would like to enjoy games like that on the go.

A Pro model can run a few of these IP and then it can run all standard Switch games (which would make up 95% of the Switch ecosystem for a while) at a better resolution and frame rate would sell quite well for Nintendo at $349.99, lets say (normal Switch, die shrunk to 14nm goes to $249.99 or less).

Beyond Switch??  Too soon. We will see 2-4 Switch revisions first. Some may act as a successor kinda like the New 3DS did or the DSi, but ask again after everything goes down next year and you may get better responses. 

I think a new Switch model will launch in march 2021 (right before the PS5 release), but it will be a slightly enhanced version of the current one equipped with tegra x2 (for better battery management and OS responsiveness) and probably 4g data connectivity. It will be called something like Switch DX and in my opinion will be sold with and without the standard dock station.

Also my prediction for the Switch 2 :D
I think it will came out by the end of 2022 or march 2023. The base model will be based on tegra xavier or its successor (Orin chipset, most probably), have a 1080p screen and 5g connectivity, bundled by default with a standard dock station it will reach about 2.5/3.0 tflops. Also from the start, a new Pro dock station (already registered patent from Nintendo) will be sold separately with an additional chipset that combined with the handheld one will grant 4k output on TV and at least 7.0/8.0 tflops. In this way Nintendo will give third parties the possibility to port their next gen PS5 titles to the Switch 2 with reasonable good graphics quality.

Current Xavier nvidia chipset:
"The most recent Tegra SoC, named Xavier after the comic book character Professor X, was announced on 28 September 2016. Its release date was supposed to be in the first quarter of 2018. It is to contain 7 billion transistors and 8 custom ARMv8 cores, a Volta GPU with 512 CUDA cores, an open sourced TPU (Tensor Processing Unit) called DLA (Deep Learning Accelerator) It is able to encode and decode 8K Ultra HD (7680×4320). Nvidia aims for a 20–30 watt TDP and the die size is estimated to be about 300 mm2. Nvidia confirmed the fabrication process to be 12nm FinFET at CES 2018." ---> 1.3 Tflops

Next gen Orin Nvidia chipset:
"Nvidia announced the next-gen SoC codename Orin (resembling the name of an aquaman comic hero) on March 27, 2018 at GPU Technology Conference 2018. Presentations already indicate that a design with two Orin chips are planned to be on par with the performance that a Pegasus board with four chips (supposed to be formed by two Xavier chips and two GPU chips) and a factor of five in performance between Xavier and Orin seems indicated." ---> 5x xavier in performance

From wiki: https://en.wikipedia.org/wiki/Tegra

Call of Duty (series), Grand Theft Auto V (w/online),Resident Evil (main series, RE7), Assassin's Creed series (main series, older AC games), could already work on current Switch, point that some games are not on Switch (at least currently) doesnt mean they are not there because they cant run on Switch.

So Pro model wouldn't improved much regardless AAA 3rd party support for Switch, I highly doubt that most of 3rd parties would want to release game that for instance could be play just small part of Switch install base (counting that those games could be run only on Pro models).