More developers will get hired, because ChatGPT will not perform the higher function tasks most developers actually spend most of their time working on.
The reason this will happen, is because ChatGPT will be more efficient in performing the lower function tasks and there will be more of a need to put all that automatically created code into actual use, integrate it with Enterprise Package FooCPT, figure out what caused the product outage at 2am at night. And on and on and on.
Not to mention that ChatGPT will not be able to talk to your users about what they want next, convince your manager that that's the right thing to do and everything else that you need to do on top of the coding part to be a good developer.
What possibly will happen is that junior developers will have even harder time getting into the industry, because clueless PHBs will see ChatGPT doing all their work "for free". A few years later they're screwed, because nobody at the company knows how their applications work. Except ChatGPT...maybe.