It's totally allowed and if you have a solid idea and good ideas about game design then AIs can definitely help move things along. And also break everything suddenly! Definitely consider the use of source control (AI will tell you exactly how to do that too if required). Then you can safely roll back to a previous commit if they make a mess of things.
For my gdtv game last year I used AI code-gen extensively (as an experiment). It worked out pretty well. All I can say is that the AIs are WAY better now than a year ago.