Provisioning of meshed FortiAP without Fortigate - IOW through FortiCloud

Hi,

I use FAP S321C using FortiCloud to administrate them. I have ready somewhere that setting them up in mesh would require a FortiGate. Do you know if this is a fact, I cannot find that info anymore? If so, do you know if it is planned in a public roadmap. Would like to avoid rolling out cable in this building.