You know your rcos, can you check luanteles rco from post #123 and see how it might be enabling the animation without any sprx patch required, it has me puzzled.
Maybe it is just a side effect of using the png or adding the text, I don't know.
I tested it last night and it showed the animation without any patch.
I added your emulator animations to his RCO and the emulators show static images, while the default page (PS3 Pro logo) was animated.
I didn't do more tests, but it may be related to the