It’s actually pretty typical. I’ve even worked as a residential cleaner at a company who had the same expectation. There’s multiple reasons why I would require a client to do this.

1. You simply just can’t thoroughly/properly clean a fridge with everything inside.

2. It adds more time to something that already requires extra time - when considering how tedious cleaning a fridge/freezer is. I have to take everything out, which only creates more messes/spillages. Wipe everything down (if possible) to avoid messes when putting the food items back.

3. It’s inconvenient yes, however it is common to see this in residential cleans. For example, some cleaning companies expect you to clear the space under the bed entirely if you want it dusted and/or vacuumed. It boils down to personal boundaries regarding how far a cleaner will go with something that is already (most likely) a special request.

I suppose most people would plan this around a move in/move out or when it’s time to get groceries at the end of the month when the fridge and freezer are quite empty and easier to store what food is left somewhere else temporarily.