I cannot believe it was Jefferies' decision to label the Constellation 1017; in an interview Jefferies gave to the BBC
, he revealed his logic for chosing NCC and 1701 in the first place.
However, most likely situation is nobody else did care that days about the label. We cannot be sure if Jefferies had a word on the label for the Constellation model. Either he didn't care, was overruled, or someone else did came up with a non-17xx number.