This happens regularly here in the Alps, it is going stronger recently, climate change? The path I mentioned above, after having being freshly marked the year before having been signed abandoned by the maintainer due to high exposure to falling rocks ā the next year suffered in a way, and nobody to repair the damage, that made me split it and mark the damaged section sac_scale=diffictult_alpine_hiking. Another year later, still more of the path suffered even more damage, so instead of marking those sac_scale=very_difficult_alpine_hiking I just marked them destroyed:highway=path and the dangling sections abandoned=yes. Idea was: On the ground, there is a trail-blazed path, and so openstreetmap derived maps should show that. The gap was sufficiently long to be noticeable on a rendered map in reasonable zoom levels. Users would be able to learn, that the path they look at just ends 500m ahead and does not connect to somewhere. That is something, that got lost with the transition to abandoned:highway=path. Yet, I did not complain. Was not in the mood for edit war or endless discussions then.
After having learned, that there are indeed consumers that honour such prefixes, I kind of think, prefixes might indeed help with what this topic about. Anybody care to come up with a list of prefixes, apart from the lifecycle ones? Iād think informal:highway=path is spot on, as not the path is informal, but the highway is 
Just my 2cents anyway.