As a GitHub engineer, as far as I know we do this because we want more users so we can flesh out bugs, but we don't want to ship buggy software. If we were to g

As a GitHub engineer, as far as I know we do this because we want more users so we can flesh out bugs, but we don't want to ship buggy software. If we were to globally ship this (even in a beta) and some really annoying bug was found, users would complain. Or if we let everyone opt in all at once, maybe the feature consumes a ton of resources and causes an unexpected outage. This slow rollout lets us keep a handle on things while still letting our most passionate users try things out.