Quoting Jonathan Carter <j...@debian.org>:
It seems clear-cut enough that it doesn't really need advice from debian-legal. If it's free software then a maintainer is free to patch out any behaviour of the app that's intrusive or otherwise undesirable. If the license of the software doesn't allow that, then it's highly likely that the software doesn't belong in main.
I probably was not clear, why I suggest to consult -legal. The question about ZZZ is not only, whether the license is free, but ads impose other legal questions, too. E.g. in some countries ads for tobacco products are not allowed. Debian cannot know nor conform to every single law in all countries of the world, but in such a case, I would discuss things first. It's different from asking for a donation to upstream.
