The PlayerBucketEmptyEvent is called above max height (256), even though it's not possible to do. BlockPlaceEvent is not called so I assumed this is not intended.

Sample code:

@EventHandler
public void onBucket(PlayerBucketEmptyEvent event) {
System.out.println(event.isCancelled());
System.out.println(event.getBlock());
}

Then go to max height and try placing a water bucket, a client action bar displays "Height limit for building is 256 blocks".

Prints out:

[23:43:19] [Server thread/INFO]: false
[23:43:19] [Server thread/INFO]: CraftBlock{pos=BlockPosition{x=1082, y=256, z=1420},type=VOID_AIR,data=Block{minecraft:void_air},fluid=net.minecraft.server.v1_16_R3.FluidTypeEmpty@f4c0e4e}