I've heard about Aftermath and Def Jam doing the same with Kendrick Lamar and Trinidad James respectively: allowing people to think the artist was still a free agent to gain buzz and then making a big announcement about a signing that happened months or even a year prior.
ive also heard rumors of that happening with A$AP Rocky, and im pretty sure it happened with wiz, he was "dropped" by one label then i believe "signed again" by another under the same umbrella
Yup. Kendrick as well. I remember telling people this here on the IC at the time Drake started to blow. I think people started to catch on right after he signed the deal.
They did it with kreyshawn, justin beiber, trinidad james, a$ap rocky, and everyone else you mention. Def jam has been doing this since the 90's, but the "indie buzz" tactic has been used for most of these new artist.