When a license “Support Contract” expires on an F5 appliance whether if it’s a Physical or a Virtual appliance, there’s no effect/disruption to the production environment configured on the device itself.
When the support contract is expired the impact is described below,

– If you come across a software issue or bugs, then you will not be able to upgrade
– No support/assistance will be provided by the vendor related to the appliance.

It’s usually advised to contact the support in case of any doubts.