Yes, the CV is retrained roughly once a month and it checks if each taxon is eligible before training on it each round.
Last winter I pushed ~10,000 Narceus americanus observations back to complex after it being in the CV for years and finally got it out. It’s frustrating because on the peripheries of the complex’s range (e.g. Texas or New England) they can theoretically be identified to species by range, and there is one identifier who still insists on doing so. But having the species in the CV would cause so many issues in the majority of the range where the two species overlap that I don’t think it’s worth it.