None I'm aware of. Short games don't really seem to have a home anymore.
I know this isn't really what you're asking about, but a few people and I are releasing some short games together on Steam as an experiment to see if we can kinda work in that space (
10mg) and there are other bundle-
like things on Steam (like Dread X) that seem to be doing well...
but it's been a time since I heard of any kind of profitable browser platform, or really anyone using any browser platform at all. (maybe i'm just old though.)
I hadn't heard about Kongregate. That's pretty sad. flash != browser games, but I don't think anyone or anything has really gathered back around the idea of building up browser games. Not sure if that's because of flash or something else.
You should still be able to get feedback lots of places though. That's an entirely separate concern from making some bucks. You won't make much $ or get a lot of organic traffic on
itch.io, but it's a great place to host web games and aggregate feedback.