I've heard the same speculation amongst active JWs, but it doesn't really hold up. AppleTV is, by far, the easiest option to use for screen-casting a tablet (using airplay) when conducting a demonstration on stage.
There are other options out there, but AppleTVs are $99, and it's a no brainer to use them with all iPads, even iPhones.
Other screencast options for mobile devices are cost-prohibitive or are technically complicated.
No idea about the man but I would agree AppleTV is by far the best wifi screencast option. Chromecast is not even close.
Would Apple be really that worried about extra revenue from deploying solutions in the WTS? This is a company that made $7.75 billion in 3 months.
If it was going to be that entrenched then lookout for AppleTV knocking Roku out on the JW TV preferred hardware list..