Yep, my own pub has 3 editors including muyself and we live in 3 different time zones.

Some of the big Medium-run publications (such as Better Humans, Human Parts...ones where the editors are actually paid and employed by Medium), often take several days to 2 weeks to respond to submissions. This is not unusual. Some give feedback, some don't.

Some editors simply don't have time to respond to every single submission that comes in the queue.