No, not in my experience. Of course "all" bike forks are plastic now, but I'm a vintage guy, so let's talk about steel forks. In those days, track forks were generally not one bit lighter than road forks. The only real differences were the blades were round not oval, and the crown height was usually lower with no mud- or fender-clearance, usually no brake hole. But the tubes and crown weren't any lighter and the dropouts were often heavier.

Two reasons why track forks were heavy:

1. There's almost no advantage to light weight on a track bike. With no hills, weight almost goes away as a factor in a race. You don't accelerate enough for the slower acceleration to be a factor, even in Match Sprint.
2. Most trackies wanted max stiffness. I was skeptical of the value of that, so I made my own track bike with light tubing, and even I had to admit, it was too flexible for me. I sold it to a skinny guy with no sprinting ability to speak of, and he loved it! Most people want 'em stiff though, even if it means heavier.

Round blades are more flexible in the fore-aft direction than oval, which makes them worse for hard braking and more prone to judder; also weaker in terms of front-end collision, or fatigue life on the road. The upside of round blades is more side-to-side stiffness, which is what track sprinters want.

Round track blades came in 22 mm and 24 mm, but the 22 mm ones generally weren't any lighter because they were thicker wall. Maybe Columbus Record had lighter blades, anyone know? Named after the tubeset made for Merckx's hour record bike. He didn't really need light-weight for an hour of steady output with only one acceleration at the beginning, but he didn't need stiffness either, so why not? They went nuts on the lightening, like leaving the hub dustcaps off so you could see the ball bearings. Major drillium all over including huge holes drilled in the handlebars. Nuts! If it made him faster, it would only have been the psyche factor, aka placebo.