Not close up they don't. It even shows a bit in your screenshot, at least for the marine. Compare what any of the male characters faces look like, in cutscenes especially, to what Captain Keyes face looked like in cutscenes in the first game and you'll know exactly what I mean.
After playing...
It's just the character models, though. I'm running in fullscreen on a 1080p monitor with forced "internal 4K", and the game objectively *is* rendering at 3840x2160 internally (F11 screenshots come out at that resolution for example). *Most* of the game looks fantastic.
All the male characters look almost nightmarishly deformed. The women are a bit better but still... weird. Whereas in Halo 1 they're just kinda "normally" low poly.
The cutscenes look distractingly bad in this, too, especially the ones focusing on Covenant characters.