Ragemage
Wept for Zion
There's no way there'll be a TES announcement, Bethesda always likes to take their time with projects; the gap between Skyrim and Fallout 4 was 4 years, you should expect that again. As a side note, I loosely remember them saying they'll be releasing a couple of new IPs, so those will probably be announced soon, though it might just be QUAKE.
You're not thinking this through right now. The main reason they always wait so long to announce new projects normally is because usually their games are fun enough to keep everyone preoccupied and not worry about a new game. For example people playing Skyrim were still finding secrets and whatnot like 2 years after the game was out, and people were having fun. Fallout 4 meanwhile is sitting at a 5.4 on Metacritic, has a Mixed score on Steam, and is generally hailed as probably the biggest gaming blunder of this decade. So they'll either have to announce some big thing like a new Elder Scrolls or have to deal with more people complaining about Fallout 4.
What I'm trying to say is, the reason they've been able to keep up this business model of not announcing anything for a while is their games are usually at least passable and enough to keep people distracted for a year or more. Meanwhile Fallout 4 is so stupid and vapid that only a couple of months after the game even loyal fans of Bethesda were calling foul and people are "waking up" essentially as more and more people get bored of FO4 and start pointing out the huge flaws with it before even a year has past. Thus Bethesda's backed into a corner right now. They can either try to distract people with some Elder Scrolls stuff (like dangling keys in front of a baby's face to stop it from crying) or let people keep realizing how shitty Fallout 4 is and take even more backlash and criticism as time goes on.