Well, we're almost three months on from this article and so far we haven't had a single SG2 referee appointed to referee a Premier League game, despite Graham Scott also being unavailable for some of this period.
If anything, it seems to have happened less over the past few years - I remember 4 years or so (before SG2 was formed) the likes of Graham Scott, Stuart Attwell and Keith Stroud being used quite a lot on the Premier League when they were not SG officials.
With the introduction of VAR, and Bobby Madley having gone and others perhaps following at the end of this season, I'm sure they will need to promote at least 2-3 officials at the end of this season.