It's kind of useful for *tube sites...
But most phones, tablets, or any other devices already have Youtube built in to them as an app.
You gotta think about it, flash has games, toons, and gadgets, and that's just basic flash with movie clips and actionscript. The companies that sell you your device don't want you playing games for free, they don't want you watching toons for free, and they don't want you using gadgets for free. That's probably the reason iPhones and iPads never had Flash compatibility in the first place. On top of all that you have "*tube sites", I'm going to interpret that as a porn site, which is a massive market. It seems like a wise buisiness choice for Adobe, not to mention it's probably a good financial move, too.
Besides, Adobe's working on a new "HTML5" project, which is more thread-worthy if you ask me.
I don't think Flash is going to have much use within the next five years. The only time I see flash animation go anywhere in on Newgrounds, and that place has gone to shit within the last three years.
And honestly, why would you need Adobe Flash compatibility on your smart phone? Do you visit addictinggames often? Because I was finished with that noise when I was eight.