Does APs needs to communicate on Layer2

[Gucamole]

We are working on blocking communication within the same VLAN, so two hosts on the same VLAN will not be able to communicate with each other. I know we can do a Layer2 host block via AP but this is more from the switch. 

We have many access points (APs) on a single VLAN. Do the APs need to communicate with each other(layer2)? If so, for what purpose?  Like do APs need to communicate for RF changes, client roaming, broadcast, multicast etc? That's what I am trying to understand. 

Can someone confirm?

[Mark Elsen]

 - If you have a controller then the access points will mainly talk to the controller only ; there are a few cases where AP's may want to communicate with each other such as mentioned in this example : https://community.cisco.com/t5/wireless/ap-communication-during-roaming/td-p/951754

 M.

[Rich R]

Also when APs do Flexconnect Efficient Image Upgrade the APs fetch the image from a neighbouring AP using TFTP.

I just noticed that you tagged your post with Meraki so that leads to the question: what type of AP (Cisco or Meraki) and if Cisco then what type of WLC and software version?
If Meraki then https://www.cisco.com/c/dam/en/us/td/docs/solutions/CVD/Campus/WhitePaper-Deploying-Cisco-Meraki-Cloud-AP-SDA-2019MAR.pdf says "The APs send untagged frames on the Ethernet trunk to communicate with the cloud,
authentication, and other management infrastructure."  There' nothing specific about AP<->AP but I wouldn't rule it out.  If in doubt open a case with Meraki and let us know what the answer is.

[Haydn Andrews]

Believe the Meraki will talk AP to AP if you happen to have the same SSID roaming accross different VLANs.