I've been reading about that!
It's actually a little trickier, or so it seems. From what I hear you can just end up with watery sauce.
I've been reading that to really make that trick work that you need to cook your pasta not quite enough, drain it well and toss it in your sauce to finish cooking, add 2-3 TBSP of pasta water to the sauce and reduce.
That's what I'm going to try.