Some issuers like Circle and Paxos are contemplating that future as well, believing that the payment networks they build for their stablecoins could be used as roads that a Fed digital dollar could drive on.
I see where they are hoping to be bought out by the government if that happens down the road, but I think they're hedging a huge likely losing risk as the government most likely would not need access to an outsiders roads when the gov has all their own superstructure already in place. The feds commented a few years ago about investigating bitcoin and it's concepts for viability.