A very well tested codebase with resilient systems and tooling takes time to learn, it will take time for a person to become productive within it - and that time is a lot longer than the 4 or so hours you get on your first day after the legal paperwork is done ;)

So pushing on day one - regardless of dangers it poses to the system - seems like pushing to production for the sake of pushing to production.

On another note though - I've worked at companies that have adhered to best practices and done remarkably well with continuous deployment and testing, but the risk of a pushing code to production is never zero. The intent of testing and resiliency is to reduce the odds of catastrophe and increase your confidence in your systems - not to make you overly cavalier.

The ticket that gets deployed is often as simple as a typo fix or a small CSS tweak, just to illustrate the whole process. The risk of deploying to prod isn't zero, but since we deploy many times a week already, the risk of deploying a typo fix is pretty low to us.

It also serves as a test for the existing employees: ideally those workflows are smooth enough that it all Just Works on a freshly-set-up environment and account, and we are comfortable enough with our rollback strategy that (after reviewing and testing) we are not afraid of merging in and deploying our new employees' code.