No, that's not really true; the PRC's position is predicated on the claim that Mandarin is a degenerate dialect of Cantonese, and not a language in its own right. They also believe, rightly or wrongly, that acknowledging the multiple Sinitic languages would threaten their status as one cohesive nation. It's also rather disingenuous to take the two component characters of 方言 apart to argue it means something different than it does; telling me it means "direction-speak" is no more illuminating than telling me "telephone" means "distant voice."