How to get frozen soup to not be chunky?
Freezing from hot isn't a good idea for the neighbouring items in your freezer but shouldn't make much difference to the soup (it will start cooling down faster, but then more slowly as the freezer will be warmer than it should be). 

Freezing the soup before blending it should help, then reheat before blending. If you are making it specifically to freeze, you could add a bit less liquid in the first place and slightly undercook it. Then you'd adjust the consistency when you reheat it for serving. 

You might also try omitting the courgette. Even cooked, courgette doesn't freeze as well as your other ingredients. It tends to go watery. It might even be better overall (though that's pure opinion).