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.
Their track record is a joke, they're biased xbox shills