Perhaps, but one need only look at the drop-off rate to determine that. We already know that Wildemount had a momentary spike at #1 of all books on Amazon (it's currently listed at 27 in overall best sellers). While it is impossible to exactly know what the sales numbers are and being ranked #27 is impressive, a drop from #1 to #27 means that sales have dropped off at least by 1/3 in only a matter of a few days. Saying that its #2 in D&D books may be less meaningful since there are still 3rd and 4th edition products listed, as well as non-game books like novels, in that category's top 100.
I'm not highly familiar with Amazon's rankings, but since it is likely #1 sold within a certain timeframe, the drop off makes sense. After all, people have bought it, they aren't going to buy it a second, third or fourth time, and until it comes out and gets reviewed, a lot of people will be saving their money. So, of course, the ranking will fall, because to keep a high ranking they would need to constantly be selling the same amount. Which is impossible, since eventually, you just run out of people.
Maybe. I'd argue that WotC's own website's tagline for Wildemount is "Create your own Critical Role campaigns with this sourcebook..." What happens when DMs and players (especially any who've been waiting for this to actually begin playing D&D vs watching a webstream of other people playing D&D) buy this expecting to be able to emulate what they see on CR? We all are already aware of the Mercer Effect regarding player expectation - whether warranted or not.
Then they grow as people.
I bet there were a lot of people frustrated that their Wood Elf Archer couldn't do everything they saw Legolas do in the movie.
Sure, some people might quit and call the game stupid and dumb, and never pick it up again. Those people were never going to stay on, because they expected something impossible. Most people will recognize that you can't perfectly imitate what a different group of people has pulled off. You aren't those people. This game isn't the Lord of the Rings movie.
So, we might get a flood of people asking "why didn't this work, why wasn't it like I imagined" and we, as more expeirenced members of the community, should gently guide them into realizing that they need to find their own way of making stories, not simply try and copy the stories they loved.
It isn't a bad thing. Just part of the hobby.