They had done a really nice build-up to the reveal of the Thargoids.
People were finding weird stuff and signals all over the place.
Somebody had figured out where to go at some point, chased an unidentified signal and got to its origin only to find nothing. He hung around a little bit hoping that something might happen after some time elapsed.
Suddenly a massive shadow fell across the cockpit and he looked up and a Thargoid (as in the video) just slowly drifted past his ship, not really doing anything and then boosted away. Whatever ship he was flying was fast and thought he could keep up, but the Thargoid just kept on speeding up and disappeared.
Since that event went public on YT, they’ve been building up to the full reveal and release of the Return of the Thargoids.
From the looks of things, they’ll kick your arse seven ways to Sunday if you try to solo them.