How can I hide the Biography and Similar Artists panel in iTunes?
I have yet to update my iTunes (and now I'm starting to think I should avoid it all together!) I was, however, able to search an Apple discussion board and found this to be the closest fix (hopefully) to what you are asking for:

Go to Edit>Preferences>Parental>Check the Apple Music Connect>Restart iTunes.

Apparently this user has a PC but they said they assume it will be easy to do on a Mac as well.
Here's the link to the discussion board I referenced. Hope this helps!