If this is a systemd distro, you can just create a timer and service. That way instead of sending a mail message, it's automatically part of the logging for that unit.
If it's a recent version of systemd, you can have a user based systemd that doesn't need escalated privileges. I just finished setting up borg for backup since I'm on Fedora Silverblue now (couldn't use the old way), and I just set up user based systemd units to do the backup.
In larger teams, you normally have 24x7 staff. So the reboot schedule goes to the current shift to monitor. It's only shops that lack round the clock scheduling that have this as a real issue, and if you don't have 24x7, shouldn't you be outsourcing to a shop that does if you really need that at all? I think that this normally (maybe not always) becomes a problem when you are dealing with layers and layers of other problems like not having enough IT staff to properly staff a department without causing unnecessary cost and risk and choosing not to outsource to an MSP/ITSP that could do this cost effectively.