We discussed this with Pranav. There are pros and cons, but we opted for the failure because:
- it's not a super common scenario to do our CI workflow on an empty github site
- in the happy path, the error is just an annoyance
- in the unhappy path (e.g. you misspell the branch), not getting any feedback is just too puzzling

Ideally, we would have a better way of conveying this message, but right now a failed deployment is our only way.