I have a user with a WxC tenant who has around 1000 manually created users. They are not using any kind of directory sync. We will soon be adding hundreds of additional users. I would like to get this customer synced with their Azure directory to make administration simpler, but I'm unsure of how this would affect the manually created users. When enabling directory sync, will the manually created users be matched up to the sync and marked inactive if they can't be found, do they stay the way they are as manual users, etc?