There are a plethora of reasons not to put sales data into github issues. I appreciate the idea of reducing complexity. Focusing things around issue tracking gives a good workflow for opening and closing, and also provids a finite goal, but theres often needs which cannot be met.
I also dont think that its necessary to point out but I would not advise handing over all business organizing to github as a platform.
Is your concern that GitHub employees might access your confidential sales data if it's in issues in a private repository?
Because if you're worried about that, there's probably a whole bunch of even worse things that they could be doing with access to your source code, secrets and CI infrastructure.
I also dont think that its necessary to point out but I would not advise handing over all business organizing to github as a platform.