Night time potty training

Hoping for some advice/ thoughts please.Our son became dry overnight for a good few weeks around Christmas time but stupidly we didn’t think to get rid of the nappies 😩. He’s now starting weeing in his nappy every night again.I heard somewhere that you can’t really train children to be dry at night,as some sort of hormone activates to wake them when they are “ready”,and he seems to be sleeping when he wees. I’m not sure whether he is having a regression,or whether the dry nights were just a fluke. My husband is keen to get a ton of spare bedding and just take his nappies away,but I’m not sure whether it better to wait when he’s dry again? He’s completely dry during the day - no accidents. Thanks