There is no good reason to veto this now and cost himself votes considering how many Democrats voted in favor including Majority Leader Chuck Schumer.
If he does, it's on par with the same "arbitrary and capricious" standard (willful and unreasonable action without consideration or regard for the facts and circumstances) that lost the Grayscale case for the SEC and led the way for the Bitcoin ETF. Hopefully he has some competent advisers that will wake him up (literally and figuratively) and tell him to sign it.