I agree with most of what you’re saying, but I strongly disagree with your proposal for a temporary solution. I think it basically ensures that we’ll never reach closure.
Marking the path with note=Disputed path is effectively akin to not marking it at all, from a data consumer perspective. This is giving the property owners exactly what they want.
Hence, they have absolutely no incentive to seek final resolution from the municipality. And, per the law, they are the only player here who can expect an answer to such a request. This leaves a situation where I never get to draw this path, like I still feel is the right thing to do, unless either the municipality or the property owners feel like being kind and providing closure.
To me that feels like an incredibly unfair deal, that would frustrate me and be bad for OSM in general.
I’d struggle to accept that outcome.
If I were to suggest a compromise, it would be to tag the path with access=unknown or similar while we wait for the municipality to have their say.