Hi,
If you have an old license, with no support, you are stuck. That is the problem with perpetual licenses. That don't live forever.
If LR dies, it may be possible that someone will replace it's functionality.
Adobe has built a path for raw image compatiblity, with DNG and DCP profiles. It may be it is not the optimal way, but it is probably the best way we have, as it is almost fully documented.
Best regards
Erik