I think that we can expect an expansion for DoWIII because everyone knows: Relic and Microsoft are working together to create AoEIV (release probably late 2018/early 2019).
Since DoWIII wasn't a success yet, a lot of people think that AoEIV won't be a success either, especially because it's Microsoft and they are going to release it ONLY on windows store to push it.
So if Relic releases a good expansion for DoWIII they are probably able to wipe out all negativity about it and A LOT more people are going to buy AoEIV.
So that are my thoughts. What are you guys thinking ?