The handling for the resolv.conf file is embedded in the libc and is larger than Linux. This whole issue is a failure of the Linux distribution community to come up with coherent standards for managing a simple text file on a system using DHCP. The solutions today are horribly complicated and appear to optimize for laptop users on simple, naive networks. I have no idea why I have to mess with any of this garbage on my servers.
No, we need to get back to software like it was in the early 2000s when people cared about consistent, long-term behavior instead of re-inventing everything because laptops.