That's actually exactly what they do for codespaces. The token only has read/write on the repo you activated for the codespace [1]. They should definitely consider doing that for github.dev as well.
[1] https://orca.security/resources/blog/hacking-github-codespac...
Also note that the person who found this was pissed because they had a difficult experience with submitting a bug for VSCode THREE YEARS AGO through MSRC which is _completely different_ than the GitHub H1 program and no doubt much more challenging with a different experience.
There is really no excuse for this irresponsible disclosure. They could have at least tried instead of holding a grudge for three years.
I agree, for the record here's my HackerOne profile https://hackerone.com/ammar2/hacktivity?type=user
Just for context, that 2023 bug was initially reported to GitHub's HackerOne program and they explicitly told me it was out of scope for them and to take it to MSRC:
> We have reviewed the report and determined that the vulnerabilities is in VS code and the fix will be implemented by Microsoft. As a result, it is not eligible for reward under the Bug Bounty program. Please follow-up with Microsoft via the report you submitted.
There was also an additional bug that allowed an attacker to exfiltrate private repo contents with a github.dev link that MSRC also marked as not having security impact.
I absolutely loved working with GitHub folks on the GitHub bug bounty program, they're responsive, go into technical details with you and are awesome to deal with. MSRC is like the polar opposite of that.