Titans and Baneblades are both mentioned in Vehicles of the Imperium, both of which are available only via Forge World rules in the main game. For the IG, we don't mention all the armoured vehicles, and we don't mention the Hunter (the only Space Marine ground vehicle in Epic but not in the main game), but I'd have no objections to doing so. We don't mention aeroplanes or space vehicles at all; the latter are possibly a slightly separate case, and possibly tie in more with Battlefleet Gothic. For the Eldar, I don't think we mention the Epic vehicles at all, but that article is very much a work-in-progress at this point; ditto for the Tau.