This is just a giant rumor... Honeywell isn't making (for a plane or not) anything that can't hold up to wifi. The EM interference at altitude makes wifi look like a joke.

The FAA directive is real. The "issue" is based on lab tests, and I haven't heard of WiFi causing a display to go blank in flight.

I talked on a cell phone in a cirrus with a glass cockpit, guess what happened? Nothing. I've also done the same with streaming music. If the displays stopped working because of wifi they would always be left trying to navigate taxiways without them... And that would be a very real problem.