Properly-designed thrust washers, with the correct clutch and properly-adjusted clutch mechanism, will not have a problem. As others have said, the engineers anticipated the force of disengaging the clutch; also, the thrust washers get oil within moments of the starter cranking.
If the clutch takes significantly more force to release than stock (e.g., racing clutch) or if the clutch release over-strokes (a HUGE problem with hydraulic release bearings), the crank can be pushed forward with more force than what the engineers anticipated. We saw that several years ago when a bunch of FF1600s blew their engines at the Runoffs -- in (almost) every case, the HRB was over-stroked, which causes a massive pressure spike in the system.
Idling for extended periods with the clutch disengaged spins the clutch release bearing, which is (generally) not designed for extended periods of spinning with pressure applied. It's happy to spin freely or to spin under pressure for several seconds, but the full duration of a red light is pushing it.
Again, echoing others -- I have other owners' manuals from equally old cars (or older) instructing you to disengage the clutch before touching the starter. I have done it both ways -- disengaging purely out of paranoia -- and always sweat just a little when I crank without disengaging.