It's this era of photography that companies like Fujifilm are borrowing their designs from, and it's an obvious next step for Canon. Taking the popular AE-1 design and digitizing it would give them a recognizable entry in the mirrorless market (something it definitely doesn't have with the M series, which is widely ignored). It could play off the popularity of similarly-styled mirrorless cameras like the Fujifilm X100T or X-T1, and it would also open the door wide for more of Canon's legacy designs to follow suit, like the A-1 or the F-1.