I agree, unfortunately without addressing the closed Source libraries in abandoned ware problem the higher issue can't be addressed which is that there is no legal obligation for a company to keep their services active, nor is there an obligation for a company to have a proper phase out of their services they could decide tomorrow to just close up and there's no real restrictions aside from Word of Mouth / PR.

As much as I would love companies being legally required to have a proper transition period into abandonware via the means of allowing the community to self host or modify their existing software, like you indicated it would put companies in a catch-22 in regards to licensing agreements. So I think the licensing issue has to be addressed first

That being said if a proper abandoned where requirement was pushed through without changes to licensing you would likely gain support of companies for the licensing problem as well because of the fact that they're in a catch-22, so at that point they have a personal interest and getting that written to law