I've noticed users that we've imported using the ZCS migration wizard for Exchange (not the PST tool) don't seem to have their reminders come over. Instead of being set to the default "5 minutes before" reminder they're set to "Never." I'm not 100% if this is all users that have been imported or just some of them as I only recently came into the migration.
It appears this guy is having the same issue.
I appreciate any input anyone has on this issue!