The ban bans ZTE from importing from US firms, it doesn't ban US firms from using US-made or foreign-made parts to repair ZTE phones. And it doesn't ban ZTE from talking to you on the phone or emailing you. It also doesn't ban ZTE from sending you updates.
(Trump is acting "big boss runs Congress" now, trying to modify the ban, but he doesn't have that power, and Congress, which does, most likely won't.)
I wouldn't worry, except for the new "security update every month" requirement - ZTE wasn't going to join that anyway.