As of 2 days ago, AT&T has only 4G and 5G.
I would assume that as long as AweSIM is based on AT&T’s infrastructure, then AT&T’s 4G data network will continue to provide a 4G data connection wherever you have coverage.
This doesn’t preclude the possibility that AweSIM could change its underlying network at some point, to T-mobile’s 4G, for example. (Or base itself on both networks combined, even.)