@andromeda087 @Midian
THEY FIXED IT! I REPEAT, AS OF PATCH 3 THE MAD LADS FIXED THE GREETINGS!
*cough*
Waited for the patch to drop and went in to test: you no longer have to trigger the thank you scene and the greetings auto-update right after you've had the confession scene now! Also, this DOES work retroactively, meaning it also turned on the new greetings for my most recent game save from Act 3 (where my Tav only had the OG confesison and old greetinfs up until now).
Thank you Larian, this has just made my whole weekend! <3