I think there will be (and there already have been) significant downsizing over the next few years as businesses leverage AI to mean the same work can be done by less people paid less.
But the job cannot go away completely yet. It needs supervision by someone that can see the bullshit it often spits out and correct it.
But, if I'm honest, software development seems to be targeted when I think design writers should be equally scared. Well, that is if businesses work out that AI isn't just chatgpt. A GPT or other LLM could be trained on a company's specific designs and documentation, and then yes designers and technical writers could be scaled right back too.
Developers are the target because that's what they see chatgpt doing.
In real terms a lot of the back office jobs and skilled writing and development jobs are on the line here.