AcoustId itself already keeps track of the number of submissions for a specific fingerprint. See the source counts on e.g. https://acoustid.org/track/82afc57c-a1a1-48f6-a1fb-5684e1a30e22
The thing is that Picard does not allow you to resubmit already existing AcoustIDs. I actually would like to have this in Picard, too, but it is probably not quite clear how this can be done.
I don’t remember the details, but we had a short discussion about this on IRC some years ago. The main fear was that if you would just be able to submit fingerprints for existing matches, that quickly would turn into a self-fullfilling prophecy: User use AcoustID to match songs in Picard, and then submit the matched IDs to AcoustId and increase the count. That way Picard would introduce a bias into the data. I still think this could be done somehow, maybe keep track of the files that where not matched by AcoustId.