BSV supporter?? Seems not because Coinbase doesnt even list BSV. BCH maybe yes. He used to be a vocal big blocker but seems very quiet ever since the insider trading allegations around the BCH listing.
i don't think exchanges "support" anything. and they definitely don't give a shit about block size, scaling or in some cases even security not matter if it is about bitcoin or some shitcoin.
i agree they shouldn't care, but it used to be a big deal for coinbase. brian armstrong constantly injected them into the block size debate in 2015-16. for instance:
when the segwit debate came to a head, there was naturally a lot of backlash against coinbase. i think 2017 was when #DeleteCoinbase became a real thing for the first time. i'm sure they realized getting involved in political debates was really bad for business.