I think the more interesting part here is you alleging a coverup of Apple supplying a review unit. Why?

I think most YouTube channels actually brag when Apple sends them review units. It’s a sign they’ve made it — their channel is influential enough to have been noticed by Apple. Most channels are happy to let their followers in on that.

My guess for what you’re noticing is that there’s also a (in my opinion kinda gross) trend of influencer types buying expensive kit, doing their review, and then returning within the window. In this case, it doesn’t surprise me that someone would spec out a unit well beyond their needs or means, because they don’t intend to actually pay for it.