it is not a standard practice for restaurant freezers to lock from the outside and not be openable from the inside. In fact, such a design would be considered a major safety hazard and is highly unlikely to comply with any safety regulations or guidelines.
Freezers, like any enclosed spaces, must prioritize the safety of individuals who may enter them. Locking a freezer from the outside and not providing an easy exit from the inside could lead to life-threatening situations if someone accidentally gets trapped inside. This is especially dangerous considering the low temperatures in freezers, which can quickly lead to hypothermia or other health issues.
In most places, building and safety codes mandate that all enclosed spaces, including freezers, have proper emergency exits or easy-to-operate mechanisms to open the door from the inside without requiring a key or specialized knowledge. These safety measures are put in place to protect employees and others from potential accidents.
It's possible that some industrial or commercial freezers may have mechanisms to lock the doors from the outside, but they would almost certainly include a manual release or an emergency escape feature on the inside. This ensures that anyone inside the freezer can open the door and exit immediately if needed.
If you have encountered a freezer with the described behavior, it might be an isolated or unauthorized modification, and it should be reported to the restaurant management or local authorities for investigation and correction to prevent any potential safety risks.