Which is nothing new. It has always been understood that it is valuable to have experienced people on board. The "cut the juniors" talk has never been about letting those who offer value go. Trying to frame it as being about those who offer experiential value — just not in the places you've arbitrary chosen — is absurd.
Aside from the absurdity of this claim, consider how many years of experience a "senior" is typically expected to have, and then consider how long even ChatGPT has been available to the public, never mind SOTA coding agents.
That entirely depends on what the experience is towards. If it is something like farming where you only get to experience a different scenario once per year due to worldly constraints, then one would expect many years — decades, even — before considering someone "senior".
But when the domain allows experiencing a new scenario every handful of milliseconds, you can shorten that tremendously. In that case, a couple of years is more than enough time to become a "senior" even with only a modicum of attention given to it. If you haven't "seen it all" after a couple of years in that kind of environment, you're never going to become "senior" as you are hardly engaging with it at all.
While anyone is free to define words as they so please, most people consider those with the most experience to be seniors. I am pretty sure that has been the message around this all along: Do not cut the seniors. The label you choose isn't significant. Whether you want to call them juniors or seniors, it has always been considered to make no sense to cut those with the most experience.