Before you say that this is intentional behavior because of MCPE-38455, well the description/summary of the issue didn't mention shulkers at all. Shulkers use to rotate their their heads from 360 degrees. Unlike mobs mobs that have a body, shulkers do not but they can't even rotate their heads from 360 degrees even though they're just heads.

Observed Results
Shulker heads don't rotate 360 degrees.

Expected results
Shulker heads should rotate 360 degrees.

This does not happen in the Java Edition. Also I am not basing my complaint on a comparison with the Java Edition.