Transplant purple leaf Prunus cerasifera
 

I am in southern california. I asked my gardner to transplant 6 yrs 15
feet high purple leaf pulm tree. He did it but I am not sure he knew
what he was doing.
I argued that the tree needs deep pruning before or after
transplanting and he said that it should not be touched.
Should I prune it? Now? (Still in full dorment)
Is there anything I can do to improve the chances of the transplant?
Thanks