Why is the siloing so important do you think? I think with all the use of LLMs now, entire functions or multiple functions can be done by 1 person. Those people can get a lot of task and skill variety in their work.
Every team member has a job to do in the software process. Each speciality can leverage AI to perform faster and better moving the whole process forward. I think everyone can expand outward with what they are able to do enhanced by AI but they need to stay around their core expertise where they are bringing the most value. Things still need to be maintainable and secure.