I don't know if this will happen anytime soon. I think there are two main problems:

1. As the article mentioned, there is a lot of growth with advertising here. Until that starts to taper off the "big" players in the podcast market (either creators or networks) will be hesitant to sign those types of deals. When they keep getting more advertising dollars it seems silly to move over to a Spotify like system.

2. Smaller players (often independent creators) are less organized and harder to get into that sort of system. This was not a problem for Spotify, or other streaming services, because the music industry had a well established Artist -> Label setup that does not exist for huge swaths of the podcast market.