Cash in on nostalgia? Come on, Star Fox 64 had undeniably the best voice acting in the franchise and it's what people know these characters for. When people thought of Zelda, Kid Icarus, Fire Emblem and all these franchises in the past, they didn't have any voices they could identify the characters with, so Nintendo could just go in any direction, but with Star Fox, everyone associates the characters with the SF64 voices. It's not about nostalgia at all.
Besides, there were redeeming qualities about Star Fox Zero, and one of them was the voice acting. The other ones were the soundtrack, the character designs, the story (sure, just another basic retelling of the original, but it was the best one so far) and a few actually great stages.