The worst thing would be CBDCs being launched in a major world currency before Bitcoin can monetises as a medium of exchange.
The political powers could then impose a ban on Bitcoin and shut down any transaction in CBDC money who they find or suspect of dealing in Bitcoin or have anything to do with bitcoin.
Bitcoin as a store of value would then be blocked. Even if we later try to build the system needed for Bitcoin to become a general medium of exchange, it could be prevented from taking off.