Some companies like Viacom, NBCUniversal and Nintendo crack down on content posted online without their consent and that's gonna target those posted on the wikis no matter what purpose they're used. To them, they're glad the rules are in place. We're not.
PenBird all the proof I need can be found on this wiki by browsing the gallery pages on the Flicky article and the Sonic Adventure article you can find enough images to see for a clear fact that they are indeed flickies and not generic birds as they share more features with them then the generic birds that can be given to the chao in Sonic Adventure.
And I do the design of them is a match to the flickies seen in previous games having the same body shape proportions and eyes as previously seen just in 3D this time. Sega doesn't need to come out and say because it's clear by their design that is what they are.