I believe the Switch will, and should, have a mid gen refresh similar to the PS4 pro and X1X in 2020.  At the very least. it would be announced no later than this.

However it will be handled more like the NEW 3DS rather than the PS4pro and X1X, where more demanding games will be "Switch 2" only and less demanding games will be released on the OG Switch and the Switch 2.  The target for the Switch 2 will be 1080p 60fps minimum while docked and remain 720p 60fps on the go, allowing it to still run the rumored PS5 (I believe to also be coming 2020) multiplat games at lower res as it will surely be a 4k machine.  It will feature the next chipset beyond a tegra X2 or a heavily modified version of it to achieve this.

Doing this will allow two things.  It will allow the OG Switch to live longer without totally shafting the install base while allowing the Switch to a healthy existence in the PS5 generation as a hybrid console.  The other thing it will do is allow the Switch brand to continue to deliver "next gen" console games on the go with concessions where necessary.  I believe it is pivital that the Switch 2 can do this as this is what makes it different than, "just another handheld."

This will leave the PS5 as the default 4k console of choice, the Switch as a capable hybrid competitor while offering basic HD while in docked mode, and XBox further exploring games as a service (likely by dragging out the X1X to exist alongside the PS5, as it would be too early to release yet ANOTHER console from them).

Thoughts?

Sure I expect an updated model, they're going to ditch the Tegra X1 relatively soon. Though I'm unsure to the extents that the new model will benefit over the original.

I don't think "more demanding games will be "Switch 2" only" will happen, or anything else in the second paragraph and beyond.

Though even if games could be exclusive to this new model, a Switch Pro released in 2020 won't be keeping up with the PS5 to get multiplat releases, the power difference between the "Switch Pro" and PS5 would almost certainly be larger than Switch and PS4, as the latter had the benefit of releasing 3.5 years later. Though there'll be a ton of cross-gen games between ps4-ps5 till 2022 probably anyway, which it could get.

But while I do expect a Switch without a Tegra X1, I don't expect it to differ massively in power from the original, the main reason for the update would simply be manufacturing reasons, making more sense to just use a new chip rather than continue to produce the Tegra X1 for years, considering it's chip used in a multitude of devices rather than exclusively for the Switch.

I expecting Switch Mini/Pocket next year and than stronger Switch in 2020.

Let's hope so, it doesn't cut it as a home console as it is now.

I don't know about all that, I do not feel any different playomg games on my Switch than I do on my PS4.

I should've clarified that it's multiplats that it compares unfavorably in - doesn't cut it that way IMO.

Nintendo's own titles, and other exclusives, are naturally a much different case.

I can accept that.

"I believe the Switch will, and should, have a mid gen refresh similar to the PS4 pro and X1X in 2020"

I agree with this.

The only way I can see this could work is that the docked Switch performance is exactly the undocked switch pro performance (384 gflops?). That would be way easier to handle for developers than making 4 different settings for one game. Add in a bigger full hd screen and people will be happy. Would be cool if the docked switch pro performance is exactly xbox/ps4 gflops. (Don't know if thats possible in 2020)

Nah much sooner than that.

It’s coming later this year or early next year.

The revision will be using a custom X2 chip.

2020 will be Switch 2. Using Xavier which will put on par with Xbox one X and 8K video rendering. One thing to keep in mind is that arm is catching to x86 very quickly. 

Apple is already will be ditching intel chips which will further innovate mobile chips.