Doubt it. Ad blockers still work on MV3, just not as well. The vast majority of people won’t notice a difference and the ones that will are the same ones that probably switched already.
Once users are forced to both potentially replace their adblocker entirely and begin mucking around with config settings and filter lists it seems inevitable that many simply jump ship. Doubly so if the advice gets amplified across social media / streaming platforms et al.
The crowd you’re referring to - i.e who follow tech news and the manifest rollout - are a tiny minority many of whom probably never used Chrome to begin with. That’s not who I have in mind here.