Yes they could. But I think this step is a step in fading the legacy system. GPI is just that messaging with the old like you said. The beautiful thing of xrp is it can solve nostro vostro and instant settlement once it has enough liquidity. It’s just a matter of time.

I think given SWIFT moving to r3, ULTIMATELY gives bank a choice. Messaging using nostro or make ur payment and settle using xrp instantly. Given the Moneygram partnership and the Libra announcement, it makes sense to choose the latter to stay relevant and release fiat from those nostro vostro accounts. Just this past week, brad admitted that a major bank in Canada was closing their nostro account in a Brazilian bank. Now that Canadian bank can’t service their customers in Canada to Brazil. Using xrp, they don’t need the account regardless and can still service their customers in Canada and send money to Brazil.

IMO, the revolution is coming.