If the rotor is not straight, then this can definitely be a source of noise. You can bend them straight with tools. If you don’t want to do this, go to your LBS and have them straighten out the rotor.
When I bought my second-ever road bike (my first serious road bike), I got it used from someone who got frustrated with disc brakes. He still avoids hydraulic disc brakes. My then-LBS was able to fix the problem within literally 5 minutes. The calipers needed to be realigned. Sometimes small things can make a big difference and someone with experience can solve the problem very easily.