Few thoughts from an outsider:
1.) HD Radio is not prevalent, but doesn't need to be. WBZ and WRKO can be streamed from iHeart's app, over the internet, and on TuneIn. I'm sure there are other places as well. I think people would be more inclined to upgrade their mobile data to unlimited before searching for a car (in this economy) with HD Radio.
1a.) Not all cars come with HD Radio. Manufacturers will put it in higher trims as a means of getting people to spend more. I argue that there are people who will save a few thousand dollars; and get a trim with less creature comforts yet the same engine performance and safety. It's Bluetooth that people want, not necessarily HD Radio.
2.) I don't see The Bull going anywhere. Country (as a genre) has more fans than anything else that is missing in Boston. And I say that with personal disdain. I'd rather have an alternative or Active Rock station, and personally don't like Country. With Active Rock, the formula is to rely on songs that will overlap with the younger side of WZLX's playlist. With Alternative, the problem is exactly the same, with some added issues. The majority of Alternative listeners are older, and will immediately start (unfairly) complaining how it's a "watered down WFNX," given that we are talking about 101.7. So, we'd have less listeners than the current station, between people who don't like Alternative and people who just want to find fault.
3. As long as they don't sell it to EMF, giving listeners north of Boston a fourth frequency (not counting HD Radio) to listen to K-Love (it's also on 99.9 up here, or at least the last I knew of), I can't take issue. (Joking, as I know that there is different coverage radii for the frequencies. I happen to live in an area where they all overlap).
4. Someone said this in the Philadelphia board, and I'll paraphrase. We can tell that it's been quite in radio, when people starting talking about theoretical format flips. I can gladly go on a tangent of what I want on the dial, but it isn't going to make it a reality.