I work in film on the distribution side (streaming film), so I see everything you're saying first-hand. However not sure what your point was with "for the time being". What specifically about my statement is temporary?
I say "for the time being," because I believe disruption (maybe not violent "disruption" in the Schumpeterian sense, but major change) is around the corner. I believe that prod co's and studios, not to mention independent artists, are going to start inking more direct deals with Microsoft, Apple, etc.
What I've already noticed is that there are a lot more players in the sales/pitch stage than there used to be. As little as 5 or 6 years ago, you basically took your show to the only buyers in town: the big 4 networks, and if you struck out there, the basic cable networks. A few incremental changes have taken place. 1) These days, the big 4 networks are seldom the only destination in the primary pitch stage. They're still the preferred destination, but basic cable is pulling numbers as big -- and sometimes bigger -- than networks, and usually offers greater creative control. 2) People are starting to pitch to Netflix and Amazon at the same time as the networks, or even in lieu of them. 3) Big companies are getting into the content buying game, in the so-called "branded entertainment" wave that's hitting Hollywood right now. These companies will typically help finance a show in exchange for product placements or other financial ancillaries.
I believe all of these things are leading indicators of more change and evolution to come. The marketplace is expanding. And the buying power of the big 4 nets has diminished in the face of the new buyers in the marketplace.
If this change accelerates, then the oligopsony on the buy side of the market crumbles, and the path is paved for broader and less channel-exclusive distribution deals.
Of course, B doesn't necessarily follow from A. It's entirely possible that we replace the current oligopsony with a new oligopsony, or even a new quasi-monopsony (i.e., Apple in the music business). But I think the smarter folks in the production game are leery of trading one total master for another, and they won't be as eager to set up a new boss, same as the old boss. Accordingly, terms on the sell side will be written increasingly in favor of the sellers.