This exactly happened to me as well in beginning of July when I dared to contact my airbnb host from different country directly from web.whatsapp on computer just after adding their contact.. Immediately saw Restricted messages, but once they answered we chatted normally and everything worked fine.

Next morning I wake up with Whatsapp account blocked (one day before flight, very convenient timing...), so immediately raised appeal, luckily account access recovered after 5-6 hours, but it made me think I should not have all my eggs in one basket (WA is only messenger I use with everyone) and since then I have also Telegram installed as backup just in case (I required IM you can use on computer from browser without installing anything, so quite limited options and telegram works exactly same as Whatsapp).