I really hope that the Thargoids don't make an appearance any time soon. The game isn't ready for aliens yet. FD really need to flesh out NPC interactions beyond the boring flight or flight dynamic. As it stands any introduction of Thargoids (that name is seriously dated) into the game would quickly become an inconvenience, just like any other NPC interdiction - albeit a more deadly inconvenience.
FD really need to take their time introducing alien life into the game. The unknown artefacts was a fantastic way of introducing mystery into the game and I hope that FD will continue to add further mysteries, puzzles and set goals that ultimately lead towards the appearance of aliens. However, despite some good initial work with the unknown artefacts I get the impression that FD peaked far too early. The initial buzz of discovery is gone and, at least in my estimation, we are left with the community desperately trying to decipher something that may not be there. (If this is the case then I think it reflects badly on FD that they have let the speculation go on for so long.)
BTW, I'm currently reading Starship Troopers so I appreciate the one-liner.