A classic book called The Phoenix Project talks about ways to manage this. If I recall correctly, teams can fall into a vicious cycle where they only respond to immediate problems and, therefore, cannot schedule and prioritize their work. By maintaining a work backlog that gets prioritized and saying no to everything else, the team can ensure their work capacity gets respected and not get flooded with more than they can handle.
So, in this way, your DevOps coworker is right. However, I don't think it's true when a team isn't at capacity, which is the scenario I envisioned when I replied. In the case where it costs little to nothing to quickly meet another team's request, the mature thing, IMO, would be to either a) do that thing or at least b) engage in good faith to put the task into your work backlog and prioritize it based on the larger impact of the overall project to the company as a whole. When a team isn't at capacity, the work would be done immediately while simultaneously reinforcing the value of the process to protect your work capacity and prioritization ability. Everybody wins.
I suppose this is what I mean by "maturity"; teams have established processes to protect the team, but if the process allows for additional work, it's maladaptive to gum up the works just to keep expectations low.
...but that response is the "full PM" treatment; that's what I'd tell my boss or answer in an interview. In reality, I think of process as a "backstop" of sorts. You invoke process only when you're reaching some kind of capacity or limitation. If it's no sweat, just do it.