It's one of those things where it's a few minutes per company per release. And then you make a new release, and have to do it again. And again. And again.
As a volunteer, it's hard to do that for software that seems to be financially motivated to report false positives, so the users can pretend the money they give antivirus companies is worthwhile.
In my case it was only one or two companies in only one release. It was not necessary to resubmit it in every release.
Also, I understand that this is not top priority and that is a nice small task to be delegated to one of the newest contributors, specially the one that have the problem and are using the obscure AV. But after a few months, it's time to say "whatever" and try to solve it. [Anyway, I tried an hour ago, it's not so easy. See my other comment.]
As a volunteer, it's hard to do that for software that seems to be financially motivated to report false positives, so the users can pretend the money they give antivirus companies is worthwhile.