I expect they might do another minor patch after Antorus / 7.3.5 similar to the minor patch that brought valor / mythic dungeons / timewalking mid-HFC, but I wouldn't expect full-scale "new zone / dungeon / raid" patch, maybe something small like another wave of micro-holidays or scenarios like chromie or the magni quest. I really don't want them to promise 7.4 and then backtrack from it. I'm quite convinced if they aren't talking about it, it's because: 1) they don't know 2) they aren't allowed to talk about it 3) there isn't really anything big planned worth mentioning, so either way talking about it would be fake hype that would end up in disappointment.