Thank you for replying to this thread and giving your point of view as a local mapper! Indeed, the point here is not to disconnect information on EuroVelo on OSM from the terrain reality. I agree with you that it is the strength of OSM, to be more up-to-date and reflect what’s really there, compared to the GPX tracks on the EuroVelo website for instance, which contain a lot of mistakes - we are well aware of this. But we cannot avoid it completely given that we receive data from intermediaries (only realistic way to work at transnational level). And as Stéphane indicated in your exchange, this type of discrepancies between the official tracks and the reality on the ground is an excellent case that we can raise with Vélo & Territoires.
I would like to clarify that the objective of this thread is not to conform OSM data to ECF data - it is to clarify a clear and coherent way of mapping EuroVelo routes across Europe, so that it would be easier to access OSM data on EuroVelo, as we know it is more complete than what is available on EuroVelo.com. NECCs decide on the itineraries of EuroVelo routes. But if the information they send us does not correspond to what’s signed on the ground, we wish to be aware of it so we can discuss it with them.