Today I drove on the now toll-free Highway 418
Regarding signage changes, they covered over the "TOLL" on overhead signs, they removed the toll tab from reassurance markers (but the blue on white markers are still there), and they added new "407 Transponder Must Be Visible" signs at the end of the freeway. I believe they might have also removed the "418 407 Transponder Must Be Visible" signs at the entrances to the 418 but I wasn't paying too much attention to that. The toll gantries are also still there.
What I think might be useful is to put a "LAST EXIT BEFORE TOLL" tab on the final exit before going to Highway 407 on the north end.