Disagree. It might take a body of work to become elite, but once elite, you don't just stop being elite because life, or the game takes it's toll on your body. You earned the accolade, you might not play to it's highest degree til the day you leave the sport, but to me elite isn't how you are playing right now, it's who you are as a player in all aspects, overall. You can't be elite today, then tomorrow you aren't then the next you are again. Rice wasn't not elite when he was a Raider, and Montana wasn't less elite when he was a Chief. He may not play at an elite level per say, but a player doesn't become less great because they age. You solidify your peak in your legacy at some point in your career, just because you don't sustain it throughout doesn't invalidate your greatness all of a sudden.
Otherwise you are just using elite to describe a current level of play. You would be the first person I have ever encountered that uses that interesting yet absurd definition.
Elite, is different than "playing at an elite level". The latter suggests that the players level of play will regress. The former suggests enough consistency that it became that high standard and expectation.