Hi, as I new person as well, take it from me, any pest hitchhikers should be taken care of in a very thorough way. They will cause problems down the line and be a bigger pain than simple taking the rocks out now and soaking them. There are probably more on the rocks you don't see and they will continue to grow and spread. I know that it is disappointing when you are so close to adding fish, but you will be thankful you took the time to deal with it.
I would also research aiptasia more if you'd like. There are some inverts that will eat them, and I believe maybe a fish or two.