DS is moving to a new university for his masters and is worried about the move and making friends. He's done some research and he knows most of his cohort will most likely be internationals.
Is it a good idea for him to reach out to school/sixth form classmates? He's messaged a few who have said how great the university is socially and have said a courtesy "yes let's meet up!". DS can't tell if they are being genuine or not. I'm erring on the side of them just saying it to be polite. DS tells me that a familiar face would do him a world of good in a new environment and would help him deal with the change.
My suggestion to DS is to go to all the mixers and join societies that he's genuinely interested in.