Why? The area between Kipling Station and Sherway Gardens is mostly industrial and commercial. It would likely continue on the surface to follow the railroad west of Kipling Station to at least Highway 427. Unless someone would be upset that a few big box stores maybe bulldozed. A few underpasses or bridges, but mostly surface running.
From
link.
View attachment 439462
The Queensway east of Kipling Avenue is slowing adding condo buildings, making it perfect for a 501 streetcar right-of-way extension to serve the new residents.
Don't forget about the Sherway Gardens redevelopment. See
link. Many of those big box stores in the area could be redeveloped into higher density mixed-use developments.