I definitely don't think Virus surcharges should be added to checks or services. No one's fault it hit us.
I would disagree with charges "Just because." However, if these charges are to cover the new expenses (like masks, having to revamp dining rooms, eliminating 50% of potential customers due to social distancing rules) then yes, I think this is necessary the same as many businesses had to add a fuel surcharge years ago when gas prices were so high.
At the same time, I feel they should consider adding a layer of transparency and either update their menus (not ideal because it would add to the expense if they weren't going to update them anyway), or post something saying "Due to new expenses and circumstances, in order to keep our lights on and employees paid, we will be assessing a $x.yy service charge to each main entree to defray costs involved with Phase Three of the covid plan. Please see a manager for an explanation of these fees if desired."