But that doesn't work. When marketing a new product, you get at most one chance to do it right. If you fuck that up, you won't get a second chance.
No payment provider is going to take the same risks for BCH again that they took for BTC. No merchant, and also most consumers won't.
Start accepting BCH, Dash, etc, if lightning works out great, go back to BTC, if not, the alternatives are there
(Of course they can look at ETH, XRP, Monero, but accepting bitcoin forks is easier if the BTC infrastructure is already there)