why do you blame them when they don't have next gen games to test it out? MH World is one of the most demanding current gen games so it's the best choice they could make. Did the people who spread the rumor about heat issues have next gen games to test? Obviously not, so this is very comparable situation.
Also I completely disagree with testing inside a small cabinet instead of an wide open surface. Series X (and PS5) is just too big to properly fit within most of these so they will likely be placed in a spot where they have a ton of open space to cool down. You wouldn't test a PC in such a configuration either.
Stress test is ment to stress something on the worst possible situation, not on a mild one. On the radios we test on the company I work we go from the lowest possible enviromental temperature that equipment would be used (something like -50C) to the highest possible (over 70C) in a spam of 10min them stay there for some hours, do the same 10min drop from 70 to -50 and then stay there for some hours, repeat some cycles so you can both test the resistance of the components (to ensure it won't have premature death due to environmental condition, poor soldering, etc) and also the protection against humidity since such harsh conditions will generate water droplets on the circuit boards. And we do that to 100% of the manufactured equipment.
Anyone that would try to prove our product work or not by doing a 20 to 30 celsius ramp in 20 min wouldn't really be doing an enviromental stress testing. And giving any credit to whatever their conclusion is would be wrong.
And again there is almost 0 possibility that Series S or X would fail due to overheating, they are improvement over the X1X that is already know to have a good working condition regarding temperature and cooling.
duduspace11 "Well, since we are estimating costs, Pokemon Red/Blue did cost Nintendo about $50m to make back in 1996"
Mr Puggsly: "Hehe, I said good profit. You said big profit. Frankly, not losing money is what I meant by good. Don't get hung up on semantics"
Azzanation: "PS5 wouldn't sold out at launch without scalpers."