If that's their excuse, why didn't they just chisel off the C???
Also, loving the zombie Cyberman...
No idea, the name dropping of Zygons & Draconians was only done as a token nod to the shows past that ultimately served little purpose so I expect the thought process was,
Moffat:"What else can we throw in there that'll look cool?"
( A production assistant checks the costumes in storage )
"We've still got some Cyberman costumes left over from the last era"
Moffat:"Perfect"