I don’t think that marketing Session in competitor’s threads is a viable replacement for lost deniability and forward secrecy, and for the fact that whoever has passphrase can read user’s messages without them knowing. So no, I don’t think anybody needs to use session, even Signal seems a better trade off. 

 how about retroshare with tor/i2p ? 

 how about briar / berty ? 

 Maybe is necessary to explain better why simplex is different then others.