Yes, we did a recent install at our Head Office of MV Cameras and these are now monitored by an ARC.
They are using Sentinel, we send motion alerts via a WebHook and they can access the cameras via RTSP over a dedicated (non-meraki) firewall we put in to terminate a Site-to-Site VPN (due to Meraki VPN only policing VPN traffic at the ingress point!)
They can also access the PA system in the Car Park over this link.
If you want to know more, please DM me and I can give you the name of the ARC.