I kind of feel for these guys. This kind of project is the worst (massive, content/maintenance-heavy website with many admin users .. urghh). And given that they are likely to be heavily scrutinized on whatever direction they take, I mean it's pretty much lose lose (I really hope they are killer designers). That said, reading the blog post took me back to 2013 .. symfony/PHP? If I was the W3C product manager I really wouldn't be confident with the technical approach. It reeks of confusion, and appears to be relying on others for technical leadership. The W3C should be leading the way here. The approach should be something you write about and people go wow! They nailed it. At the moment it sounds like someone's googled accessibility and is in the process of pushing high-contrast lemons through the orange peeler.