I reckon Apple Intelligence will end up solving this problem - have it classify notifications and then give you control. That way, you're not reliant on ongoing good behaviour from developers.
There's no reason to believe they would want to offer this feature, even though it is indeed trivial for an LLM or even a basic regex filter.
The current iOS version already does this to a degree: if you use profiles. It notices if you often interact with an application during X profile and asks if you want to add it to that profile's allowed apps.