I don't think this is a good idea in the long run, but I could certainly see it happening in the not-too-distant future. I think we're already moving toward a future where we get the unbundled cable service we thought we wanted in the form of a dozen separate streaming video apps, and I don't doubt that streaming music services are going to push for ever-greater numbers of exclusive premieres, back catalogs and even original content. The question isn't whether producers will try this with podcasts, the question is how many producers will try it--and how successful it will be.
There definitely doesn't seem to be a ton of money in podcasting right now. Many of the heavy hitters in that world regularly ask for donations from listeners.