I think that’s the crux of the issue is rebble isn’t under any obligation distribute them open source, unless say the original app had a “copyleft” policy?
AFAIK the original apps were individually licensed by the creators... so Rebble would need to have permission before claiming anything for their own except in the case of explicit permissive licenses (like MIT). In some cases (copyleft licenses) Rebble would be required to make their maintenance also open source.
