It's not really an Alderaan type event, though - it was an unhardened megaship with no escorts. A single Cyclops could take that out without trouble and everyone knows it ... and of course the Thargoid attack on the Kingfisher was itself carried out by the Stargoid's interceptor escort, not the Stargoid itself.
We had the "Thargoids have decent firepower" event when they were taking out Farraguts off-screen back in 2.3.
Given how much the front 3 have slowed to a crawl in the last few weeks - I wonder if they were originally hoping to release U14 a couple of weeks earlier, and have had to add in some filler to pass the time.