U can see it even on 5090 with max settings(ray reconstruction included):
Watch whole 20min and judge for urself if u can somewhat tolerate it or(like unfortunately for myself) its way too distracting, hell some ppl might not even see it(godbless their eyes) so best if u check for urself, doesnt work with some1 else telling u one way or another.
That problem exist coz game is very light on the gpu's vram, even max settings dont change that too much, so personally hoping if not for patch then a mod that can fix it- coz in my layman eyes/terms i would describe it as simply game assets/lod transitions arent using of stronger gpu's vram pool enough.
Max i ever saw was 12,8gigs vram taken on 5090 and trully max settings (native 4k,cinematic, rr, dlaa) like here:
Obviouisly its cranked to 11 if u set game settings to low like here( non remastered oblivion/gothic nostalgia warning

)
Under those settings pop-ins have their own pop-ins