"If a student has previously been granted permission on the Tier 1 (Post-study work)
route, International Graduate Scheme (IGS) or the Future Talent Working in
Scotland Scheme, this will not prevent them from meeting the validation
requirements of the Graduate route. If a student has previously been granted
permission on one of these routes, the student will need to successfully complete a
new eligible qualification at a Higher Education Provider with a track record of
compliance and hold valid permission as a student once the route is introduced, they
cannot rely on a previous qualification obtained or previous leave as a Student or
under Tier 4 to access the route. "
https://assets.publishing.service.gov.u ... 1.0ext.pdf
The above paragraph clearly means that anyone who had previously been granted PSW or IGS are eligible for New Graduate Route scheme.