Do they work there or not? I deeply appreciate that everyone's threat model is different, but I'd bet anyone that wants to create a new DNS record also has access to credentials that would do a ton more actual damage to the company if they so chose

Alternatively, yup, SOC2 is a thing: optionally create a ticket tracking the why, then open a PR against the IaC repo citing that ticket, have it ack-ed by someone other than the submitter, audit trail complete, change managed, the end

What's your threat model that says they shouldn't? If you don't trust your senior devs, you're already pwned.