I like Lubuntu and often use it for low powered devices and sometimes devices that aren't so low powered. This phrasing is a PR blunder in my opinion because the old focus is a lot clearer than the new focus. Here's how you should have said it:
We are focusing our resources on developing a fast, clean, functional distribution for devices manufactured in the last ten years.
Then you can go on to explain the rationale (which is all quite sensible, if you don't want to support hardware that's 15-20 years old, you don't have to, it's a pretty niche market anyway).