I suppose it's an inversion of the same theme, yeah.

IIRC, Pterry is talking about this line (or a similar line from Small Gods, not certain) and the Sapir-Whorf hypothesis in The Folklore of Discworld - I think he's actually bringing up (and dismantling) the Eskimo line in that context. But I'd have to look it up to be sure, it's been a year since I read that. Or it might have been on tvTropes. *scratches head*