i want to visit the U.S. in September; currently feasible?

i’m thinking of going back to the States for a month with a Japanese friend to visit family and show him around.

i already know that the U.S. has virtually no entry requirements. as for Japan’s re-entry requirements, i was told that 3rd-vaccinated people just need a re-entry permit and a within 72-hour PCR test (along with passport and visa obviously), but is there anything else that i’m missing?

i also read MOFA’s border guidelines and there’s a paragraph about visas issued before December 2nd, 2021 being suspended; it’s not very thorough so i’m just wondering what that’s about?

finally, how risky is going home now in terms of being able to come back ? especially with COVID cases in Japan going up and monkeypox cases soaring in the U.S., i’m worried that the Japanese government is conjuring up something. when COVID started i heard stories about foreign students with visas going home for spring break and suddenly being locked out for over a year, and that’s the one thing i’m trying to avoid. in other words, how much of a guarantee does the reentry permit grant someone in the event that border measures become more strict?

sorry if most of these are searchable questions but hearing first-hand-experiences really gives me peace of mind; i spent nearly a year and a half locked out of japan before finally being able to come and really don’t want to go through a similar situation again 🙁

btw i’m on a two-year student visa issued in July 2021