Just to clarify a bit.
I am not suggesting we remove packages which fail to migrate from github/sourceforge to a more complaint hosting environment. A decision could be that we ask existing maintainers to move and require that all new packages from a specific date are only on a supported hosting environment. I raised this suggestion now specifically with respect to non-GNU ELPA because that is a relatively new repository and as such, it could be a good place to start with for establishing a repository which is more in line with FSF philosophy and goals. In some sense, it could be a testbed to refine a more general repository approach that might be applied to GNU ELPA at some point in the future.
I would never agree to a 'name and shame' approach. That is seldom an appropriate course of action and can only be justified when there are very serious direct consequences. What we want here is increased incentive, a carrot, not a stick.
With respect to Github and Microsoft, I have little confidence in the proposition we could put pressure on Github to adopt practices that are in-line with FSF philosophy. Microsoft is a public company run by a board of directors who have an obligation to maximise the share prices and dividends for the shareholders. Ultimately, decisions are based on maintaining and increasing profit. The ability to make decisions to further such profit generation is closely tied to control. This makes any decision which gives up control less likely to be welcomed. I have little confidence Microsoft would be willing to give up the level of control necessary for it to become accepted under FSF guidelines as an ethical hosting provider. Some minor cosmetic changes might be possible, but little more. We would probably have better success moving Gitlab from Class C to Class B with respect to providing an FSF compliant hosting platform.
My main point here is that many of the problems associated with maintenance of packages, such as issue tracking, are being significantly complicated because the code is being maintained on a platform which does not meet GNU/FSF guidelines, philosophy and goals. If a key goal of the FSF is to promote an ethical position with respect to software, it has to prioritise that ethical position over convenience. Convenience is probably the number one threat to software freedom. Rather than focus on the inconvenience of requiring maintainers to use a more appropriate hosting platform, consider the potential benefits with respect to issue tracking and maintenance that would be possible without the limitations and confusion caused by the current situation. Furthermore, consider the benefits to the core message of having an ecosystem which is actually based on more ethically compliant systems.