Gauld is at the right place for him, regardless if Sporting have the best youth coaching or not. There will be an emphasis on technical ability rather than "toughening him up" which you know is pretty much the end game for most youth developers in the UK.
I would expect him to feature for the first team sporadically this season and then either be promoted or possibly go out on loan to a senior team next year. No reason to think he wont have a successful career - hes already shown he can comfortably play at Scottish Premiership level and, like others have said, isnt a bam which seems to be the downfall of many young Scottish players.