I got Arbiter on my first account in early 2021 the first time the "bots" showed up. This was before I'd figured out how to gear my champions, so they were mostly wearing maxed-out flat attack gloves and similar garbage.
So, needless to say, it was very easy to do it back then. Certainly easier than it will be after the missions revision Plarium's going to make now.
That's not to say I'm opposed to a legacy skin. I'd like more "bells and whistles" in general. I just find the sense of entitlement implicit in the OP sort of annoying, as it would be if some Boomer in 2022 complained to a current college student about how tuition used to be $100 a semester or whatever.