"Podcast Subscriptions." Feh. If ever there was a more contradictory term. Podcasts are free, they're meant to be free. It took over a decade of lawsuits and patent troll fights to keep them that way, so excuse me if I balk at anyone celebrating Apple's weak attempt at going back in time in the wrong direction.
Eh, there already are podcasts that are subscription-only, and have been for a long time, and if the podcast creators want to do that, that's up to them. Apple is only offering a "we take care of all the details - for a price" way to do something that was already around. This isn't Apple trying to start the world down some new dark path.
What's different is that you can only play these podcasts in Apple's podcast app, which has not previously been particularly attractive to use, in comparison with the pile of really nice third-party podcast apps out there. I'll stick with Overcast, and only use Apple's app in the unlikely event I run across some subscription podcast that I can't live without.