If the cooldown rate is increased, the overall cooldown time decreases. The tooltip isn’t really wrong, just poorly phrased. There are plenty of examples of tooltips that don’t describe spell behavior perfectly.
I know dude, that’s what I explained earlier about how it’s displayed differently depending on your UI. It’s possible that you changed UIs (or UI settings) from one that displays net cd time to one that displays it as faster tick rate, which isn’t as obvious.
But hey, if you’re so confident about your knowledge, why do I even bother.