Can't be sure but would say the FR focus on Scottish announcements will be exclusively to do with STN. If you've got 80 PC of activity at a major south east gateway why not push for 90, 100??
A GLA kick off on STN is also in line with recent FR moves - developing more main airports, Athens, Lisbon, BCN instead of girona, Brussels at the expense of Charleroi, Main Rome airport. Logic says GLA over PIK, STO over Skasta, Belfast over Derry??.....time will reveal.