Angel isn't the overall player Nneka is, but she's an animal on the glass and high energy defensive player. Finding a player like Angel who doesn't require a lot of shots and is willing to do the dirty work at a high level could be exactly what Team USA needs to compliment more polished offensive front-court players like Stewart/A'ja.
Angel doesn't project to be a better player than Nneka, but the level of competition among posts isn't going to be nearly as strong as it was in 2016/2020. In both 2016 and 2020 Nneka was passed over in favor of Tina Charles (2012 MVP), Sylvia Fowles (2017 MVP), Breanna Stewart (2018/2023 MVP), Brittney Griner and Elena Delle Donne (2015 and 2019 MVP). Not to mention Candace Parker (2008 and 2013 MVP) was left off in 2016, and A'ja Wilson (2020/2022 MVP) who also beat her out for the 2020 team). That's a LOT of MVP players plus Griner she was competing against.
Looking ahead at 2028, the post depth isn't nearly as deep. Only Wilson and Stewart remain as likely picks from potentially 5-6 post picks. Griner is an option but she'll be 2 months shy of 38 the next Olympic cycle, and Alyssa Thomas will also be 36, so neither is a lock. Looking at the other options you have Aliyah Boston as a likely future Olympian and maybe Dearica Hamby but I think Angel is right there in that grouping.