Well, it doesn’t make much sense as a marketing ploy, because it’s not like there’s currently an option to pre-order the entire catalogue, thinking you were going to get demos for all songs only to learn later that it was just a ploy to take your money. That would be a marketing ploy. As it stands, no one is going to be tricked into buying demo-less reissues when they don’t want to?
Further, I would point to the copy you highlighted yourself as reason to think demos for subsequent albums will be released:
Quote:
“PJ Harvey will re-issue her entire back catalogue of studio albums on vinyl as well as release separate 'Demos' albums – featuring demo versions of each album track, available for the first time as a complete stand-alone alone collection – on vinyl, CD and download over the next 12 months.”
This states explicitly "demos for each track published on all her albums", I don't know how else it could be interpreted.
Although, I wouldn’t be surprised if some releases featured a mix of B-sides and demos. Nothing concrete making me think that, aside from the Rid Of Me/4TD release already deviating from the “demos for each song on the album” template.