A toaster (at least a cheap toaster) is an electrical device, not an electronic one, as stated by the author in the article. Please look up the difference if you don't know what it is.
Even cheap toasters (I take toaster apart for fun) have true electronics these days because it's usually cheaper to implement things like timers electronically and if the toaster has a display it certainly has some electronics. But I suspect that the absolute simplest toasters are purely mechanical and electrical.
I was curious so I did some searching -- this is the cheapest toaster that I'm aware of in the US, and it surprisingly does have a custom IC that handles the timing: https://www.youtube.com/watch?v=zLFG068HtgM