He didn’t change the law. He was already able to run since it was for a Federal office. It’s been that way since before he was governor. The legislature simply clarified that and that a currently employed state official cannot run for another state office in or out of Florida.
Anyone running for the presidency has some degree of self-service involved, with the possible exception of George Washington.
I must have read something incorrectly. In any case, he’s still a weasel....but I don’t have a vote, so my opinion is irrelevant.