To clarify a bit. The worry was not so much it was showing where a military base was as it was reveling details interior to a base that are intentionally not on a map and leaking details on where people moved and concentrated. Honestly, like the parent said, probably harmless info for the most part. But it is an additional set of data points that could be useful to an attacker.

I don't think it's indeed possible to hide a military base in the modern world anymore. Even a sufficiently motivated citizen can track them with the various public channels so for nation states it's even easier.

On the subject of Russia, it's such a studied country that I'm convinced there's intelligence actors which have a better view on the exact state of their own military than themselves.

Since you're not calling Russia a nation state, does it mean it can't track various public channels?

They can but I doubt it's any useful when the almighty dictator won't ever listen any bad news on the state of their own army. Getting the data isn't the issue here, we're on a dictatorship paradox.