I will believe it when I see it. I have been feeling really helpless and hopeless recently about Windows. So hopefully this news turns into something real.
There are other quite elegent methods for triangle and simplices.
For a triangle, drawing α and β uniform over [0,1) the barycentric coordinates given by (1-sqrt(α), sqrt(alpha)(1-β), βsqrt(alpha)) is uniform over the triangle. No rejection and no test for flipping.
For simplices (triangle, tetrahedron, 5-cell etc) barycentric coordinates obtained by drawing uniformly from (0,1] taking a log and normalizing will be uniform within the simplex.
I wrote about this and other related sampling below.