Its a good thing for promotion of biking culture in Pakistan, as we(most/many of us) now have something to grow to after 125/150cc bikes.
I think people are just repeating what they said before motorway opened for public, years ago, Accidents, Shohdas, Over-speeding, Deaths and all. Did it ever actually happened? I don't recall. It should be the same for bikes.
I travelled on the motorway in Jan and Feb this year on a bus, sitting right behind the driver with an excellent view. Between Islamabad and Lahore I saw 6 to 8 Radar speed traps on our side of the road and 3 of these with a car stopped next to a motorway police vehicle a short distance ahead. Two of these were in Kallarkahar area where the speed limit is 50-70 km/h. I am sure when they allow bikes, they will put extra radar speed traps.
Lets hope that everything goes well and in the near future the engine size limit is reduced to 400cc and then to 250cc at a later stage. And maybe then some big manufactures would bring in these bikes and train their workshop staff.