Source: https://twitter.com/TerranGregory/st...83583875497984
Terron Gregory is the in-game cinematic director, he also works on TRAILERS.
I think it might be a hint that we will see something exciting at Gamescom.
EDIT:
So Ion Hazzikostas confirmed in the interwiev that he's going to Gamescom. Also he talked about a lot of 7.3 stuff in that interview so my question is - why would they fly him to Europe if there wasn't an expansion announcement?
I don't think he would go there to have a 5 minute panel on which he would reveal 7.3 trailer.