World Height Limit Changes Do Not Apply In The Nether and The End

In 21w06a, the height limits have been changed, with the low end being y=-64 and the high end being y=320. However, in the nether and the End, that change is not seen.

 

Expected: The height limit is supposed to be 384 blocks like in the overworked.

 

What Actually Happened: The height limit still uses the old system (21w05a or earlier).