They will likely revamp the process. The problem is, once the ballot is counted, the vote is separated from the voter, so there's no link to who the person was and who they voted for.
It's a process meant for privacy. That someone was able to accurately forge signatures enough to pass verification (which is handled by trained humans) is a bit on the "this was creepy/planned" side, which is likely how the outlier event happened.
America isn't there yet, but cryptographic hashes anonymizing but connecting a vote to a voter, so the vote could be anonymously recalled for an attack like this would likely be the best privacy-preserving process.
It is always projection. There have been previous Republican voters fraud cases in the last election(s).
At least it's an easy alert for what problems to look for. If they're declaring "the other guys" are doing something, they're already doing it themselves.