In context, Harry is asking about Sickles specifically, which are silver & not gold. So Griphook's reply is consistent with the Stone being able to do both silver & gold, as well as the classical Stone's exclusive gold*. If Harry had asked about coining a ton of Knuts or Galleons and Griphook had replied assuming silver, then that'd be strong evidence the Stone only did silver in the MoR-verse.

*I've done a bit, not that much, of reading about alchemy; I don't remember the philosopher's stone ever supposed to be able to do silver in addition to gold.