Here's a link to help clarify things.
https://promo.espn.com/espn/accn/faq
Starting at item #21, which is the current list of TV providers, it makes clear that if you don't have a cable TV provider who has signed up, you won't be able to watch ACCN. Item #25 confirms this...
"Can I pay to subscribe to ACCN online, Pay-Per-View or via ESPN3 if I can't get it on TV? No. The games will be exclusive to ACCN and ACCNE."
The really confusing part is that for several years now they've seemingly bundled ESPN3 (computer) to the WatchESPN app (Roku, Apple & mobile). I'm not a cord cutter yet, but even paying extra for the WatchESPN app via Roku, there's no channel for ACCN. This would confirm that there's no cord-cutter option except for the newly released agreement with YouTube TV.
The downside with YouTube TV is that you have to purchase the whole bundle. You can't just watch ACCN, which would be ~ $65/mo. To JD's article on the homepage, Amazon & Disney have no love for each other, so I'd highly doubt that ACCN / ESPN would reach an agreement with Amazon. Disney wouldn't allow it. Plus, that's not necessarily Amazon's game plan... or Apple or Netflix's either, for that matter. Apple & Netflix are going after original content. AMZN, Apple & Netflix may offer a few sep. app options, but ESPN has not shown any interest in going that route. With the exception of Disney's new channel coming up in November, ESPN has still aligned themselves to the cable TV model ~ which would explain the agreement with YouTube. YT is simply a new method of delivering cable TV. It's a different model than Amazon, Apple or Netflix altogether.