Sure. The problem is just an easy fix that nobody there thought about yet.
There may be non technical reasons for it, even: legal, or PR, but if they want me to believe the "scalability excuse" they need to convince me they're trying.
I suspect that rate-limits would fly in the face of a lot of narratives like “Azure is ready for hyperscale”. And getting eyes on Github is probably a part of their Copilot product strategy.