Did they release the server components for hosting your own snap repositories, yet?
I can't seem to find it. Any pointers would be helpful, so at least I can know the latest state of this thing.
No, but it's trivial to implement since Snap is open source so you know exactly what sort of payload it wants.
Snapd still hardcodes Canonical's snap store signing key and provides no mechanism to add your own keys. Any other snap repos will be treated as second class citizens.