Suppose you learn somehow (from contracting the hotel or whatever) that it isn't a qualifying rate. What would you do then? Reserve under a different rate plan, cancel the trip, stay elsewhere, etc.?

If this is some business trip where you must go, must stay in that hotel, and must use the reservation you have under the locally negotiated rate, asking in advance won't matter but it might reduce the chance (however small) that you'll ge given credit by mistake.