Fake Google accounts signups on Play Store app

Has anyone had any experience with fake accounts on an app available on the Play Store?

Within the first 24-48 hours, around 20 accounts "signed up" to my app (i.e. accounts were created via Firebase, but these weren't replicated to my app database so they were clearly scripted/fake).

All were Google accounts, with e-mail address formatted "firstname.lastname@gmail.com".

I saw something similar when I ran an AdWords campaign a few years ago - email registrations with the same format that just smelled wrong.

I mean, it's easy enough to flag these as fake, so it's not an immediately pressing issue. I'm just wondering whether it's something I need to be mindful of from a security perspective.