I believe they ask for a permanent US address along with SSN. Not clear on how I can provide a permanent address while filing as a non resident after moving to Canada (not a gc holder and was on h1b in the US)
If your account access is dependent on your US phone number (e.g. for retrieving passoword etc), then your access could be affected if it doesnt allow other method of authentication. This affected me for my Robinhood account, but it was empty so I didnt bother.