From my personal experience over the past year:
GO in Y/PEY: high chance to have greeting from SP
GO in J: very low chance to have greeting from ISM (when the ISM did greet, it's most possible the ISM is the type that greet each and every J pax regardless of status)

DM in Y: 95% greet by SP, FP or at least BC (the 5% no greeting happened in CAN route)
DM in J: ~100% greet by ISM (so far all ISM did manage to talk to me some point during the flight. On one flight as I was frantically taking photos of the cabin, ISM came to check if everything's alright. I'm not sure if I should count that as a greeting LOL)