I believe this to be the case. I just wrote in the Bastoni thread but it seems like a combination of factors has allowed this deal to happen.It’s been in the pipeline for so long. Suspect there was a handshake agreement or maybe even a contractual one allowing him to go if he stayed another year. Happens much more often in Italy than here with the closer relationships between chairman of clubs and also agents.
Bremer extended with Torino purely as a favor so they could get some more money. In exchange, they wouldn't stop him from leaving by asking for a ridiculous fee, and he would be able to join the club of his choice - which, thank Christ - seems to be Inter.
Additionally, Torino need to replace the outgoing Belotti and they seem keen on Inter's Pinamonti. So there's some more leverage there.
As you say, this happens a lot in Italy. Relationships between club CEO's and Sporting Directors is immensely important and as a result, these club officials attain much more public notoriety too. For example, I can name pretty much every CEO and Sporting Director / Technical Director in Serie A but only a handful outside of Italy. In England they have a much lower profile and things are done much more "by the book".