Some level of power creep is needed. Using the next ds toon as an example, he should be better than jmk but jmk should still be able to survive in arena. Jml and See should also survive to and extent since they are recent metas. Slkr and Rey to and even lesser extent since they are less recent metas.
On the one hand, a new meta shouldn't destroy the previous one to the extent that it has no value in arena but you also shouldn't be able to farm one GL and expect it to be top 10 arena viable for the next 3 years.