Didn't the UK park have leaked concept art? It's assumed that concept art doesn't represent the final product, but still. Also I thought we knew Universal was up to something in the UK before they made an announcement, did we not? And staying in the UK, the park hasn't even broken ground, so there are years before we can safely say they kept things under wraps.
Also if we're including parks outside of Orlando, the F&F ride at Hollywood has had a mountain of leaks.
The newest attraction in Orlando, Villiancon, had tons of leaks too. So I'm not really seeing a trend in them being any more careful than they have in the past.