Other way round
FrequentSLF
NO - if there is NO OVERSPEED PROTECTION it means that famous HAL will NOT interfere when speed becomes too high.
The speed limit is then lowered to 320 kts, meaning, pilots, don't fly at a speed above 320 kts. The reason for this lowering of the limit speed is so that you will have a larger margin to the real limit of Vmo, to give some leeway in case you do a sloppy job of monitoring your max speed limit. With HAL operational, IT will do that monitoring job for you.