I think you massively overestimate the amount of users that are
a) affected by this
b) reporting it
When seeing the overall picture, this might mlbe a rather fringe issue in Google's eyes.
Furthermore, you might be exaggerating the impact as well. The "impact" is that an app update fails. That's it. That might be annoying, but isn't the grave and evil thing you make it out to be.
Besides, have you ever thought about that this stems from a rather bad practice on F-Droid/app developer side? They use the same package name for a software with a different signature. That's just not ideal to begin with. All packages with the same name should have the same signature for any given version of the package. That's how security works. If they don't follow that, how is a user/security software supposed to check if the signature is authentic or of the package was tampered with?