Personally I would not measure the intensity of a resurgence in film photography based against levels that it previously enjoyed before it’s demise. Instead I would try to measure any new growth against the low point in film’s use. As to whether or not a true renaissance is happening, or is possible or is just plain ludicrous depends on each individual’s point of view. With that in mind I suppose some sort of agreed upon standards would need to be established. One of those would have to do with the documented opening of new film processing labs. Another would surely have to do with the introduction or the reintroduction of film options that did not exist at films’ low point. Another measure would of course be the introduction (or again the reintroduction) of film cameras that do not currently exist.
I realize that this this last unit of measure is the least likely to happen but also the single biggest indicator of a true renewed interest in film by both photographers and industry alike. I’m sure that this is the event that most would never see happening. People used to say exactly the same thing about turntables. (At one point in the late eighties after I bought a new turntable I literally could not give my old Technics turntable away. When it became apparent that no one wanted it I sadly ended up throwing it out in a dumpster as I just didn’t have enough storage space for it.) So I’ll go out on a limb here, purely for the sake of conversation, and predict that we’ll see a film camera introduced by someone other than Leica within the next five years.