I disagree. The 3DS and Vita should be moved to legacy, which I'm sure they will be anyway. Since Nintendo and Sony no longer have those systems in production, they are effectively dead. So it's time to close the door on them once and for all.
However, the PS4 and Xbox One are still in production, they're still being supported, and Sony and Microsoft are still making money off them. So they still have plenty of life left in them and I don't think it would be appropriate to consider them legacy platforms just yet.
Look above, the 3DS and Vita are under the legacy label. I didn't think it was necessary to mention that they should be removed altogether in 2021; I don't know why the Vita has still been in these articles when it sells absolutely nothing.