You will see and hear it in post first. No more ADR, captioning, and Assistant Editors will be less valuable because the machine can log and stem the footage on its own. Edit time will be cut down as the basic cuts and coverage can be automatic and they can go right to comparing takes and adjusting for beats. The building part of VFX will be greatly simplified too. I don't think the editors/IATSE have as good of a standing to bargain against it, plus their contract phasing will be behind the times with regard to AI.
I think writers will be aided by it and the WGA will get some concessions to protect themselves. Sure AI can write, but it still will need people to do the finery at least for the near term. So it is more of an idea generator in that sense. Yes, many shows are pitched with only a logline or outline and greenlit without a script, but they must have a creative package that can execute. They need an experienced producing team and writing showrunner and a star attached. They will still get paid to deliver scripts and execute the show.
That said many streamers now will, (instead of ordering a pilot or going straight to series) approve a "mini writers room" to write the scripts and then greenlight the series going forward based on what comes out of that. If the WGA gets good protections there (minimum staffing, premium rates) I think they will be satisfied.