This feels like the same question as in consumer goods: "do I buy this thing now, or do I wait for the potential refresh in 6mo to see if it's better?"
Just get the thing you need now, there's no promise the grass is getting any greener, nor that you're any better off waiting. Maybe the LLM won't learn for 6 months. Or 12 months. Or maybe the AI company will run out of money, or jack up their prices to where you're not using it anymore, or whatever.
