The underpass will remain 6 tracks with this project but before the widest span held 5 tracks (because one bridge was on its own on the east side) and now the widest span will hold 6 tracks. There will likely be a project to add more tracks to this structure in the coming years. The Georgetown South EA has 8 tracks through this area and funding recently announced (long after this project started) allocates money to be spent on this structure as well as Dupont, Bloor, Lansdowne and Brock. Knowing the bridges at those locations can already 5 at Bloor and Dupont, 6 at Lansdowne, 7 at Brock, and 6 on this structure it seems obvious that they are targeting the full build out specified in the EA which is 6 at Bloor and Dupont, 8 at Lansdowne, Brock, and 8 on this structure which has been built for 6 tracks plus a pedestrian component originally.