I think we are going to see widespread interest right away, with a noticeable number of priests at least dipping their toes into the water over the next 6-12 months. Many will probably receive little or no positive feedback from either their bishops or their parishioners — as I trust they expect. Of these, many will be discouraged and give up the project. What’s needed is an appreciation of the intrinsic value of the traditional rite — an appreciation that fear of congregational displeasure is itself one of the bad fruits of the misbegotten reform, which degraded the Mass into an applause-seeking performance.
Lex orandi, etc.: Both clergy and laity need time to allow liturgy — any liturgy — to form them, either for good or else not-so-good. IMO a year or two of weekly celebration/attendance at the Extraordinary Rite will be needed before it starts to feel like “home”.
You know this is a good point — since the Traditional High Mass isn’t dependent on the personality of the Priest it should not prove to be terribly intimidating. I hope they will do their best to do it well, but if there’s a certain amount of muttering, so be it.