All the reviews are linked by email address, so Brenna can still see them all. You don’t need to do anything other than write reviews and apply for testers in the #testers topics. 
The old review profile links that we put in our forum profiles are dead links to nowhere now, so you can delete them from your profile whenever you like.
The My Reviews topic is for if you just want to share your reviews in one place again. It’s nothing to do with testers, it’s just a forum thing. 
As you can’t link to specific reviews now they’ve opted for this rubbish yopto review app thing, copying and pasting any of them into that topic means you can link to them if they ever crop up in a forum conversation, etc. As yet nobody but me as done that, but I have noticed a few copy&paste reviews popping up across the boards, so I’ve got my fingers-crossed. 