It's not a surprise for me. The problem that was coming from SEC against binance US has been triggering binance US's partner to feel doubt by facilitating binance US to access USD. I guess if the banking partner of binance US has become the main problem that makes binance US suspends its deposit and withdrawal for US next week. It's not a complicated situation. Binance US's partner was feeling worry to deal with binance after it has been getting major problem against SEC.
It's caused by binance US partners are not willing to join in the problem that already faced by binance US.