As we all know, Binance is one of the top crypto trading platforms, ( if not THE top). Not following the rules in Japan will cost them to loos this market, which will drive the BNB to go down ( as there are huge number of traders on Binance are from Japan). then it will create kind of fear which will lead other traders to sell BNB. Therefore, i dont see Binance will drop this market share and hand it over to YAHOO easily.
If Yahoo enters the market, then the competition will be tough as they are new in the space and will take them time to get to the same level of other trading platforms.
Lets wait and see. as long as we dont lose money lol.