This Binance news probably won't have much effect on Bitcoin.
Although Binance is the largest exchange in terms of volumem Bitcoin has been traded in the US for years now so having a new office open can't have that much of an effect. There may be new traders registering, but given KYC is also required the same way, they probably already have accounts on Coinbase and are already trading nonetheless.
It will give some effect since this legalization will increase the number of traders in Binance, this will also increase the demand where a lot of investors will be added and coins to be transferred to Binance.
Legalization of binance will be the first step for some other countries to accept crypto in their countries. This will become the trigger for them to move and start to accept crypto from now on.