The Omnibots (Omnibot (G1) - Transformers Wiki) are a faction of Autobots who have the ability to deploy custom tech from their vehicle modes, usually wings or weaponry (Camshaft, Overdrive, Downshift and possibly Tracks). They were never a really popular faction: all they got were some toys and a handful of appearances within the comics. With DOTM introducing the concept of Stealth Force, it would appear that the Omnibots have been rendered obsolete. With the Autobots now upgraded to be able to carry specialized gear within their vehicle modes, it removes the Omnibots’ uniqueness and renders them no more than the average Autobot. It’s a pity, because I’d have liked to have seen a TFilm version of Tracks. He’d be in en elite club, with the Delorean (BTTF) and the Ford Anglia (HARRY POTTER 2).
No, they still had characterizations outside of their "omniparts", but they're not characters that have seen a lot of attention. If anything, I'm happy to see Stealth Force revive the concept the Omnibots used.