HM, if TRs are necessary for stopping on poor runway conditions, does this mean that aircraft become undispatchable if they have inoperative thrust reversers?
Aircraft with unservicibilities are dispatched with reference to the Minimum Equipment List which lists the requirements to dispatch with whatever the particular unservicibility is.
It may be that a particular problem leaves a particular aircraft serviceable for some flights but not others.
In the case of Reverse thrust, it would most likely be a case of calculating the dispatch landing capability of the aircraft WRT the conditions forcast at the destination with the TRs unservicable, and if sufficient runway was available, the flight could dispatch.
It is impossible to make a general statement, as it would require the particular combination of aircraft/MEL/destination conditions to be assessed.