does the moto g4 play use gsm or cdma service
It will use either. What you get depends on what the coverage check shows. If certain phones are excluded then you will get on configured for CDMA. If no phones are excluded but you have a CDMA phone now you will get a CDMA phone. Otherwise, it’s a toss up.
just adding a BYOD Moto G4 play will be GSM as all BYOD are GSM