Reverted with https://www.openstreetmap.org/changeset/166730199.
I explained the reason vor "vehicle =destination" in in https://www.openstreetmap.org/note/4733518, there is also a link to Youtube where Regionetz explains how the construction zone and the closings work.
Routing with "vehicle=destination" works as expected: https://www.openstreetmap.org/directions?engine=fossgis_osrm_car&route=50.779071%2C6.082821%3B50.782368%2C6.077231.