Submarines can also be detected by sonar. Ships are common and do not raise as much suspicion as submarines. Either could have launched the divers.

can you deploy divers from subs?

You sure can! It was used quite extensively Operation Ivy Bells: https://en.m.wikipedia.org/wiki/Operation_Ivy_Bells

this is amazing! Tysm.

Yes, it's common practice, and has been for decades. It is my (unfounded suspicion) that submarine-based divers were the ones to destroy the Nordstreams.

Easily. It's one of their most used functions.

Sheer hubris, knowing the media will carry water for you later.