I'm similarly lost as GP, and even reading this, I feel like I'm missing something.

If HN said they're disabling new submissions and comments, that'd effectively mean they're closing the site, and would probably say that outright.

But Glitch aren't saying they are shutting down, but they're removing the feature that I thought made Glitch a thing. So nothing is left, yet they continue? Is this a 180 pivot or? Are there other features that will still be usable?

It could go the Piczo route—a website builder aimed at kids and teens, not for polished blogs or ecommerce, but more for one-off, personal and playful friend-to-friend sites.