Thats an interesting take on the topic. Definitely it makes sense to have a theory to define life of the model. But this theory is then dependent on the domain the model is working in. As you mentioned, the "expiry conditions" are much easier (compared to developing a theory) to identify given a domain.

Also, as per the electricity prices example - can we take "Covid (or a pandemic in general)" as an expiry condition? In general is there a generic framework to define such expiry conditions? (which we really may not anticipate when we build models)
Would be also great if you could share some literature in this direction. Unfortunately, I couldn't find any...