I have no idea if the "dedicated" flash system changed from the earlier non-AF cameras (FD lens mount) to the EOS series cameras. Some things about flash autoexposure changed from film to digital, as autoexposure on film was metered off of the film surface during exposure. The digital sensor is not as reflective so such metering is not possible, and digital SLRs have a different flash metering system.
You probably would be able to trigger the flash but not meter the flash exposure in the camera. For auto flash you may be able to keep it in self-metered thyristor mode and set the camera manually to correct aperture and shutter.
Thyristor auto-flash was the earliest auto-exposure mode for flash photography. Before that you had to use the flash unit guide number and look up a table by film speed and subject distance what aperture to use. With thyristor flashes you just set a single aperture and the flash could see its own light in the photocell and shut itself off when enough light had been projected onto the scene.
"Dedicated" flash units came out which had extra contacts in the shoe to communicate with the camera both directions. The camera could know when the flash was ready, and the flash could instruct the camera to set the shutter to sync speed, and set the aperture to the required opening. Those functions will probably not work on your newer camera, but I can't say for sure. The fact that it tries to do that may interfere with trying any manual or thyristor modes.
So IF you can force the flash to auto-thyristor mode, and IF you can set the camera manually, it'll probably be OK. Anything more advanced than that, even if it says it's doing it, will probably fail to expose properly, or fail to perform at all.
In my own Nikon experience, the SB-24 I had on my n8008 failed to perform at all on my D50 and D5000 digitals. Going the other direction, though (new flash/old camera,) my current SB-600 works perfectly on my F4 film camera.