Just a note for others in case they were puzzled (like I was), but a few minutes of research today confirms that Apple has not graced any of their legacy Apple TV's with the ability to acquire the app needed to utilize Movies Anywhere. That is only possible (meaning, only allowed) with an ATV4.
I have multiple versions of Rokus of various ages that sit in different rooms in different cities. All of them were up and running immediately with Movies Anywhere. But not with Apple. Contrived obsolescence = obnoxious money grab.
Well done Roku. Epic fail Apple.
"Get me a scotch. I'm starving." JVC DLA RS-540U, Stewart ST 130 G3, Yamaha RX-A3080, Emotiva XPA-3, Panasonic UB820, Oppo 103D, Xfinity X1, Roku, ATV, Harmony 900. Atmos 7.2.4 via Martin Logan Stage-X, Martin Logan Theos x2, Martin Logan FX x2, Sonance VP69 x2, Sonance VP66 x4, SVS PC12-NSD x2. Viewer's choice between Palliser recliners x7 or Great Dane beds x2.