I don't believe this is true at all. HDMI 2.0/HDCP 2.2 means different hardware.
There are no physical differences, so its a question of whether or not the device was prepped for HDMI 2.0 and/or HDCP 2.2 or not. The device itself may be ready, but the firmware and software needs an update to support it. Getting from HDMI 1.4 to 2.0a is not a problem if it was built 2.0a ready.
On HDMI Support:
http://www.digitaltrends.com/home-theater/hdmi-2-0-explained/
As to the issue of HDCP 2.2 support, that's a separate matter, but it is possible to use a firmware update if (big if) they built the device to support it. The rest of your communication chain has to support 2.2 so that's a whole other mess. If you look at the back of the first BD player, there are two HDMI's. One to run to the receiver, the other to the display. That's a pretty ugly work around. My display and the BD player will support it, but my processor will not so that's going to cost some money.
That said, if the HDMI can be updated from 1.4 to 2.0a by firmware, then the ATV4 as a device would be able to support 4K film at 24/30 FPS which would be bueno. I still want my stinking 7.1 audio!