Anthropic is better about this, but then shifted their ordering with the v4 models. Arguably better, but still quite annoying since everything pre-4 uses a different naming scheme.
As for this Gemma release, I don't think Gemma 4 would be an appropriate name. 3n is limited to very small versions (like 8B total parameters) and is therefore likely less powerful than Gemma 3.
From my impression this is more like a "Gemma 3 Lite" that provides a better speed/quality tradeoff than the smaller Gemma 3 models.