I understand why this is a tempting thing to do in a "STOP THE PRESSES" manner where you take a breather and fix any existing issues that snuck through. I don't yet understand why when you reach steady-state, you wouldn't rely on the same tooling in a proactive manner to prevent issues from being shipped.
And if you say "yeah, that's obv the plan," well then I don't understand what going closed-source _now_ actually accomplishes with the horses already out of the barn.