Gramps respects copyrights, even Ancestry’s onerously broad ones. To build-in such a datascraper feature (that you suggest should already exist) would require an extravagant provenance tracking system & copyright compliance system. In essence, any material sourced through Ancestry cannot be freely re-distributed.
Even if you choose to upload exclusively owned media to Ancestry and then download for import elsewhere, you have agreed to overlay their terms & conditions on that fork of digital property.
I, for one, recommend NEVER passing data through Ancestry. Although, you might use them to point you in the direction of the data source … where you can acquire usage rights without their highly restrictive overlay. So long as it isn’t done with a tool the violates their T&C.
I don’t expect Ancestry to be anthing but jerks about this… to the point of slapping violators (& enabling tech providers) with punitive lawsuits.
With an estimated 3 million customers paying $25-$50 per month (many at promotional discount rates), they’d be darn foolish to make it too easy to harvest the data and cut that revenue stream. They DO have commercial agreements with some partners. But I’d hate to wade through the contracts, penalty clauses & payola involved.