Worked in a care home, we screwed dado onto wall to act as a buffer from chair backs bashing and scraping the walllpaper, long screws sunk into dado and then filled.
Another care home the handyman had gripfiled th dado onto the wallpaer , so when the wallpaper was stripped, off came the dado rail as well, then at a private house the dado had been grip filled to the plasterboard walls and plastered brick walls, both walls damaged trying to remove it, plaster off, plasterboard ripped.
Best idea is to score the wall along the top and bottom of the dado rail to stop the plaster,wallpaper pulling off the wall further than the width of the dado.