Seems unlikely. Fuses, MOVs, and clamp diodes cause signal integrity issues (especially at 3.3V and under). And, for 200 lines, the cost might be impressive.
That said, if the Pi foundation can arrange for all the I/O to come out of reset in a hi-Z state, then there's a chance they could arrange the rest of the pins to avoid damage.
But would it be worth the effort? Given how hard it is to access most sodimm sockets, mistakes seem rather unlikely.
Do you think they've fused it so it doesn't short out and trash any board you put it into by mistake?