This depends…
If the change is that there’s an entire street in CityStrides that shouldn’t be here at all, then the update in OpenStreetMap will make it “invisible” to the query … This would result in the street being deleted from CityStrides. That should also automatically remove the manually completed street.
If the change is that a piece of the street is private, then the update in CityStrides will be that the street is just somehow changed (I won’t really have a view of what changed, how it changed, etc - I’ll only know “this is different now”). The exact same situation is going to occur when I finally get streets updated so that they don’t extend beyond city border - a piece of that street will go away.
So this “street update” scenario is where the two options come up.
There is also the idea: Remove 'manually completed' feature … so if that’s the goal then automatically unsetting manual completions on street updates seems reasonable. If completing streets manually is only a way around bad data, then if the data is fixed then it seems to stand that the manual completion should be removed.
lots to think about 