Fedora release cycles: longer or shorter?

Fedora is very unlikely to do any such nonsense. Moral obligations if any are different from legal ones. Trying to confuse them would lead to the path of XFree86. If all software Fedora includes demand such credits, we would obviously go nowhere. So let's not even suggest using the legal tool to do the job. I don't a silver bullet solution to what essentially appears to be a marketing problem but this certainly isn't it.