One other thought: does the Orbi run in router mode (as in, does it manage a LAN within the Verizon router’s LAN / its own routing tables)? Or is it running purely as an Access Point or Mesh hub / node?

Does the Orbi have extra LAN ports, would plugging the Apple TV & FIOS box directly into the Orbi allow them to work wired?
(Since they’re close, you might be able to more easily hide those wires.)

If the intent of the person who made the suggestion was to move these two devices off the WiFi connection, that might address what they’re looking for…
(Though personally, I’d first want a full, clear explanation of why this was asked for before doing anything.)