Partially. Part of the Seretean is a shell over the Auditorium you see in the background of the photo, which was renovated into the Concert Hall. The rest of it was new construction that covers the space between the two buildings and part of the Williams Hall footprint. The rest of the Williams footprint is now a parking lot.
It was an architectural loss for sure, but by most accounts I've seen, Williams Hall looked a lot better than it functioned by the time it was torn down.