Yeah, as echoed by some on the linked topic, the seeming lack of any press release, the fact that there seems to be no other games published on the App Store by the same developer, makes it tricky to verify whether it truly is an official game or not, to say the least. You would think that if Sony is affiliated they would bother to show that somewhere in their youtube video. Unless Sony actually sold their rights to Lemmings completely over to the developer, which would be quite surprising.
Also, I can't find any cost information (granted, I don't have an Apple device so I'm only going by what the App Store shows on the web browser). Is it a paid app or freemium? If freemium, how are they making money (ads? in-app purchases for extra levels? etc.) It's hard to imagine an official release without some component of this, heck, even unofficial games I'd expect to see the same.
I don't follow Sony closely so I don't really know what their mobile strategy, if any, is nowadays. Maybe a poorly announced mobile app is not all that inconsistent with their overall mobile strategy, but somehow I can't imagine that to be the case.
And yeah, I won't be able to try it at all if it's not on Android. Oh well.