I don't recall Aegi being good in either vgc or bss tho, which makes it a weird nerf.
Unless they were scared of someone dinamaxing a shield-form Aegislash? I wonder if Max Moves will trigger his form change
Aegi has always been great in BSS, it's been consistently on the most used mons list.
I don't know much about VGC, but I recall it being good in some non GS Cup formats.