Still think this is a pipe dream based on costs alone.
But beyond that, Sony is absolutely going to go camera based inside-out for their next HMD. I almost feel like "wireless" will be a harder sell than tethered in this scenario. They're finally getting rid of the clunky external tracking camera, and now they're going to tell users to plaster a big clunky antennae high up on their wall and run a cable to the PS5? And make sure you have complete line of site to the HMD at all times (or else the image crashes). Even ignoring how expensive it is, it just strikes me as going in a direction Sony doesn't want to go (ie making things simpler and an easier sell to the SO).
Which is why I still think a hybrid system is the most likely. Not only is it cheaper, but it doesn't require anything plastered onto the walls (and unsightly coaxial cables running down from it).
Every single headset priced for regular consumers will be inside-out within two years for sure. Outside in will be limited to expensive high end sets for extreme hobbyists, plus commercial units.