First, if you did have GPT-X (say GPT-10) in your company, there wouldn't be much back-and-forth communication either. Those parts would still be handled with GPT-X talking to another GPT-X in the other company. Even the requirements might be given by a GPT-X.
Second, even if that's not the case, the part of doing the communication can be handled by non-programmers. Then they can feed the result of the communication to GPT-X and had it churn out some program. Perhaps would keep a couple of developers to verify the programs (sort of like GPT-X operators and QA testers) and get rid of the rest.
As for the rest of the current team of developers? GPT-X and the people running the company could not care less about them!