It does. It will always do even after how many mining happens. What mining does is only cuts miners’ rewards into half but it doesn’t make mining not functional anymore.
No there’s no such thing as mining plan expiration unless you are subscribing to a specific platform. Which I don’t think is even possible. But you could buy mining hardware and software, all differ in prices depending on the efficiency of each so it is also difficult to calculate the point where you start earning profit without the actual costs.