I'm very glad for Q coming back, because, like I've said after the season finale, he's the one person in the entire universe who can finally settle this debate about Picard's identity once and for all. If he treats Picard like the real deal as opposed to a copy, then in my opinion it'll be a very clear indication that an actual transfer of consciousness took place.
Not that any kind of confirmation would be needed. Just like how we couldn't conclusively confirm whether Data had a soul or not, there's no way people other than Q could tell the difference. If it walks like Jean-Luc Picard, talks like Jean-Luc Picard and is the only instance of Jean-Luc Picard in existence, then it's Jean-Luc Picard, and I'm hoping the next season will actually touch on this thought experiment. I'm quite sad that in place of a very interesting philosophical debate about the nature of consciousness and if mind uploading could be considered a legitimate way of extending one's life, we only got two camps of people dead set in their ways, one taking a transfer of consciousness for granted, the other declaring him to be an off-brand mechanical copy or at best a separate person without any deeper considerations, simply because it presents them with a convenient crutch that allows them to disregard any later seasons of another "not true Trek" on the grounds of "not being about anyone I know or care about".