Well in general you shouldn't need to routinely check for Program Updates, as the default settings are set to Ask, so it checks automatically if a program update is available you get a notification pop-up Asking if you want to install it now.
That said, it shouldn't require a restart unless an update was found and you applied it.
I checked mine, existing program version 7.0.1426 and off it goes to check at the end of that check it reports I'm up to date, I click OK and it is done, no restart required.
So this will need some avast developer input.