In her case, Her sexualization complaints are probably going to be referring to comments that are overly vulgar and downright violent. Think about all of the vulgar, potentially sexually violent PMs she gets, these racists are sick and we can't dismiss that, just because she did a photoshoot in lingerie.
At the same time, as you stated the world is full of trolls and POSs, and because of that, women should know that posing in racy outfits or nude (this is in reference to Sydney Sweeney's recent complaints about being sexualized) will come with criticism but given the fact that Naomi Osaka whose most revealing pictures are in basic bikinis, has also been on the receiving end of this shows that Angel's complaints along with the fact that she mentioned death threats are probably focused on the nastiest and violent comments and not stuck up Karens or some old Boomer whose pissed that a Black woman has the nerve have a personality.
While Lebron James was not sexualized (or maybe he was), remember how vitriolic people were when we decided to sign with Miami, this is probably what she is facing on a daily basis.