there was also a pre-order duty free service so i hope that has been looked into if any such orders were on-loaded at SSH
AFAIK duty-free uplifted in DME
Kulverstukas maybe knows more on the type of catering actually on board?
I have no reason to doubt link you provided to Metrojet own site, but last year traveler reports shows hot meals on SSH-LED leg. Also it was Egyptian catering IIRC.