Deepslate (not variants, only deepslate itself) slabs, stairs and walls are removed in 21w08a (when cobbled deepslate and cobbled deepslate slabs/stairs/walls were added). This might be intentional but it wasn't mentioned in the 21w08a changelog and inconsistent with stone.
Might relate to MC-222728.
Comments 8
@unknown You're wrong. Only cobbled/polished deepslate and deepslate tile/brick slabs, stairs and walls exist. Regular deepslate walls, slabs and stairs don't exist unlike when deepslate was first introduced in 21w07a. This must be reopened.
They're still there.