If Disney didn't throw the streaming services into the deal, Charter would still be blacking out ESPN and Disney, or Disney would have had to cut its carriage fees. Ergo, streaming is propping up linear. In any event, the deal is a transition from a dying linear model to streaming. Expect more of the same.
That cordcuttersnews link is a much better analysis of what happened than the other link. I think of these small channels as having been a step towards streaming that has become obsolete. When the cable technology reached a point where channels became much cheaper to add, all the major broadcasters started adding them. 30 years ago, there were 3 or 4 HBO channels, one of which was the same as one of the others, just 3 hours ahead. By the late 2010's, there were something like 10 HBO channels. There were 13 or 14 Starz channels. Disney had 8 or 10 outside of ESPN.
All of those channels could survive because viewers wanted niche programming and because the broadcasters could push through incremental carriage fees. With the cable providers and aggregators pushing back on carriage fees, some of these channels are no longer viable. But the viewers of those channels will still want that content, they will just get it through a streaming service. If someone has young kids, and Disney Junior is taken off the air, it may be time to just bite the bullet and cut the cord. The kids need their Mickey. Every time one of these channels is removed, it makes the cable bundle less valuable, because more people will then cut the cord looking for the content that they want. If they have to pay for a DisneyPlus subscription anyway, then what are they doing with cable? Which is why Charter wanted the DisneyPlus subscriptions as part of the deal. Charter no longer has to pay for niche channels but its customers still get the niche content directly through Disney.
Every article I read about the Charter/Disney deal, the more it becomes clear that Iger is trying to pretty ESPN up for a sale. Disney took a major hit through its niche channels and streaming subscriptions to maintain ESPN's carriage fees. He needs the carriage fees to make ESPN's long-term profitability look better as ESPN pays increasingly higher prices for sports content. I doubt a buyer of ESPN will fall for that shell game, but you never know. Iger only needs one to fall for it.