The market of "people who don't have Internet access" is becoming increasingly smaller all the time. I hardly think the general argument of "there are only a limited number of spots, therefore the record labels serve a purpose to control access to those spots" applies to the general market of "all people who want to listen to music". Most of them have Internet access.
YouTube may be only able to show so much on its front page at a time, but it can change more rapidly, there are powerful and easy to use search capabilities that go far beyond just what is on the front page, and theoretically there can be an infinite number of YouTubes. Nobody is stopping anyone from creating their own site to promote certain types of music, or whatever niche you listen to.
The point I'm trying laboriously to get to is that for the vast majority of the music listening public, you're not limited to listening to whatever happens to be on the radio. The need for a record label to compete for limited airtime to promote their artists just to make them visible to you just isn't there anymore.
As a TekSavvy customer, I can guarantee you we either aren't being throttled, or we're getting around it. I used to be on their DSL service provided by Bell's last mile, and I've since switched to their cable service on Rogers' last mile. It's true Bell throttled all of their lines, including the wholesale customers, but TekSavvy specifically supported MLPPP on their precisely to get around this, so it wasn't an issue for anybody who was actually, you know, tech savvy (pun intended).
Rogers doesn't throttle their wholesale customers at all. It's always possible they might start, but with Bell backing off throttling now, Rogers is the only major ISP left who is actually throttling at all in Canada, as far as I'm aware. I think it's highly likely Rogers will soon be going the same route, and extremely unlikely that they'll go the complete opposite direction and start throttling everybody the way Bell was.
If the reason for this change really is because they've got all their customers on UBB plans, then the independents like TekSavvy have an even bigger advantage over them than before. Their caps are huge in comparison (300 GB on every one of their plans, and unlimited options available).
People will buy anything that's one to a customer.