Yeah, it's one of those things that catches out new Requiem players who didn't read the manual on a semi-frequent basis.
Draugr are mid-tier enemies, you need fire/silver/restoration magic to effectively kill them. If you're an archer, silver is necessary, as they take no damage from other material types (and you can forget your sneak bonuses on undead, fetcher). There are also some other changes to the final sections of the dungeon which make it even more challenging.
This may seem like difficulty for difficulty's sake, but it's to make sure you're strong enough for the next section: fighting a dragon. Dragons are significantly buffed high level enemies who can plausibly destroy a large town and kill multiple guards or soldiers (Requiem guards are significantly buffed, so this is no small feat). In older versions, this would also cause random dragon attacks to start. Irileth and the Whiterun guard will help you with the first dragon, so it's not so bad, but fighting a dragon on your own is a whole different story.
Not that it matters much for my character. Dunmer = best race. Plus fire magic and Red Eagle's Bane = curbstomping undead.
Beyond that, I think the idea was also to emulate Morrowind, where Snowy Granius and the bandit infested Dwemer ruin often brutally stomped unprepared players, before telling them to go back to Balmora and git gud.
