This seems like victim blaming. Removing the app from the play store seems like much too harsh of a punishment for a simple procedural oversight. To me it seems like a more appropriate response would have been to give Briar a 5 day window to supply credentials and leave their existing app in the play store.
To me, it sounds the other way around: how good is a test if the tester can't even figure out something that basic? They might follow some strict scenario, but if it's that inflexible, it still casts doubt on the quality. But yeah, just complying with google's rules seems the easiest way out of this.
It's likely automated, so they wanted to have some data to type (even if it's arbitrary such as this case) in for the automated tester to move forward.