This is probably a good discussion for: Gemini API - Google AI Developers Forum
Long term interactions API is going to be the only supported API.
I completely understand why Google don’t want to alias “gemini-flash” → latest gemini flash. Prices vary wildly between models, 2.5 flash is way cheaper than 3.7 flash and both are supported atm.
You are going to need to watch this stuff, LLMs are moving very fast now.
Note that Gemini have actually moved slower than Anthropic or Open AI this year.