Can't say the sense it gave me involved humanity being threatened. :7
I guess if the Titans just pull up their tentpoles and unceremoneously trundle off, I guess the Thargoid mystery remains, and they stay a menacing unspeaking presence in the dark, but... I don't know -- I have only watched the war from the sidelines personally, and done some argueably "peaceful" bits, so I do realise my insight into all the efforts is very limited; And given the means, the players who do involve themselves have beaten back the front, for sure; But... it still doesn't feel "earned"... From a storytelling perspective... Does that make sense?
If this is the end of the main plot arc, I think it would feel very sudden, after things have been drawn out for so long, and so little has been revealed.
Much of that comes inherently with the MMO nature of the game, of course, and I am the sort who typically play games to experience the story, which has never been what Elite is...