Solder comes before temperature stress tests, not after. Otherwise, the non defective units would have had a different design. OTOH, other components might have had poor heat tolerance and also needed replacing. 

Simply put, the issue wasn't cooling the console so much as making sure it would work at that temperature. Cooling problems imply fan failure or mechanical issues slowing heat exchange. 

Fair how? You say most people without even an ounce of evidence, not to even forget that you can use Series X on its side.

The fact that you use it on a specific way doesn't mean most do. And if you don't have a demanding enough game then you better not try to say you really tested it. And the lack of games that could do it with a month to launch isn't problematic? Even more when you put that MS have the second place on most games available at launch?

And on the second paragraph I said enough times in the thread that there is zero reason to suspect overheating issues with Series.

Probably not hard to find. I'll just look at the videos where he stops bashing Sony and starts bashing Microsoft. I imagine it's a money thing. Sony fans far outnumber Xbox fans and, though there's money/views to be made by being contrarian, there's probably more money to be made by going with what's popular. People eventually get bored watching content from someone they disagree with.

He should have ditched the name "crapgamer", though. Hard to take him seriously with that monniker.

The guys make some of the worst clickbait content ever. Zero integrity and spin fake news like no other.

His content and viewers breed negativity and hatred. 

Anyone that takes him seriously should really revisit their life choices. 

My bro bought one of those Nyko Intercoolers not that long after purchasing the white OG 360 model, since he had read about it's heat concerns. While after over a decade of casual use, he finally got the RROD, but I don't think it had anything to do with the Intercooler. A bunch of the capacitors were blown and worn out and needed to be replaced. After reading about the caps, which there wasn't much info, it seemed like they were a lower grade product, which a few online with repair experience had said were more rare to find in 360's as though they were only used for a limited time for whatever reason.

It fired up right after replacing the caps, though both the internal fans weren't working, even without the Intercooler. I would've assumed the system wouldn't allow it to run like that in the OS menu, but it did. Since the Intercooler provided plenty of cooling itself, I just cut the internal fans out of their housing to remove the blockage, allowing for better airflow. I also cleaned out some minor dust, replaced the thermal paste, extended the heatsink shroud, etc, and it's run great ever since.

The exhaust was quite warm but not hot, which it should be, because the heat transfer efficiency is higher now with new, better quality paste. Plus better directed heatsink airflow. Though how hot the exhaust feels, will also depend on how much air is being pulled through the system. The higher the airflow, the cooler the exhaust will feel, in comparison to lower airflow and hotter exhaust. The Intercooler moves quite a bit of air, so the exhaust will never feel hot. Along with that, the higher the airflow, the faster the fan has to run, so the louder the noise levels. The Intercooler has tiny fans that run at high RPM which are loud and make my PS4 seem reasonably quiet.

That's way over a decade running with the Intercooler, so I'd assume in your case that it was either a bad batch of Nyko product, or MS was using that as an excuse. 360 had a ton of issue's that they obviously didn't and don't want to admit to in detail. They just paid to fix the problem while keeping the hardware issue's as quiet as possible.

They have heavily focused on fixing those weaker points of their XB hardware products ever since though. They clearly learned a lesson with 360, but also learned a lesson with XB1, that the answer can't simply be just make a bulky bland boring console, to house a bulky fan and heatsink to fix the heating problem. That lead to even better hardware in terms of the XB1S and especially XB1X.

If XBSX is running a little hot, the problem is highly unlikely to be another RROD like with the 360, it would be more of a long term RROD in terms of longevity possibly. Electronics are made to run warm in general, and can be designed to run hot, or even really really hot. That costs more though. They have to balance product cost and longevity, along with noise, etc, so it's a game of wait and see. Odds are by the time it could potentially be a problem, if that ever comes to pass, it'll be last gen outdated tech already.

My bro's Intercooler plugs in pretty snug. I could see an issue if the user didn't push hard enough to ensure a solid connection. Pretty hard to believe it was that big of a manufacturing tolerance issue for Nyko that they didn't realize it until there was a ton of products sold to consumers and didn't recall them. Could be, just kinda tough to believe.

Mind you, it's tough to believe MS themselves would launch XB 360 as they did and ignore the RROD as long as they did. Yet MS eventually made good on those problems, so why not Nyko? Business is business I guess.

It is a non-issue. It's by design.

The RROD cannot occur with the 8th gen or 9th gen devices, long before failure can occur the consoles will throttle their clockspeeds and if that isn't enough, enter thermal shutdown to protect the hardware.

It's a PC technology, it's been around for decades now, it works.

Metal expands and contracts with heat. - This is basic thermodynamics. (But I wouldn't know anything about heat, would I?)
The solder would expand and contract with the heat and start to produce fine hair-line cracks, which is why people would cover their Xbox in a towel in order to bring the heat level up high enough to "reset" the solder, but that was only a temporary solution.

It is because the solder wasn't designed to tolerate those heat levels like the older lead solder. - That is down to the cooling design in the Xbox 360 not being up to snuff and the materials being used.

The PCB would also "warp" and buckle compounding the solder issue over time, again, poor thermal design and poor supports.

The same issue would occur on the PC, some older GPU's would have the PCB flex over time, newer GPU's now come with a GPU back-plate which keeps the PCB torqued and as straight as possible.
The older Geforce GPU's would also have the solder joints fail due to heat stresses over time as well, which forced nVidia to do a recall, it's the same issue the Xbox 360 had ironically.
https://www.cnet.com/news/summarizing-the-nvidia-problems-with-laptop-chips-overheating/
https://techreport.com/news/15720/chip-failures-nvidia-responds-at-last/

Well, now that the devices are in the hands of end users: how alive are these overheating rumours?

I have been playing mine for a couple of hours everyday, and even left it on a few times AFK.  Fans are damn near silent and I have had no issues.  The air coming out of the top does not feel any hotter than the air that comes out of the back of my PS4 Pro.

I would like to note that hot air coming out of a console is a good thing. That means the system is removed heat adequately if needed.
If the XSX had a worse cooling system the air removed wouldn't be as hot as the heat is being trapped inside the console.

The PS4 Pro cooling system isn't crap because hot air is coming out, it's crap because it's loud as a mfer and also indicates that the core temperature is too hot and heat is not being removed efficiently from the SoC, and just overall annoying.