Correct. Well, almost. Early reactive armor is only designed to interfere with HEAT ("high explosive anti-tank, a.k.a. "shaped charge") rounds. Newer reactive armor can also interfere with AP.
And in case anyone's wondering, it's been around since at least 1982--there are pictures of Syrian tanks in Lebanon which have it. It gives them a texture kind of like The Thing from Fantastic Four. The U.S. uses it too.
That part in M0 where Roy's 1S has reactive armor doesn't strike me as particularly accurate, by the way, but since I've never seen a super slo-mo of a round hitting reactive armor, I could easily be mistaken.
Well, I thought HEAT rounds WERE a kind of armor-piercing weapon.
They sure punch through it well enough...