Rectifying mismatched pipe heights for a thermostat shower without stripping off all the newly tiled walls can be challenging but not impossible. One potential solution could involve using adjustable pipe connectors or extension fittings that allow you to adjust the height of the pipes without disrupting the tiles. Alternatively, if the height difference is minimal, you might consider installing decorative covers or trim plates to conceal the inconsistency.
If the pipes are accessible from behind the wall, a plumber might be able to adjust their height without removing the tiles by accessing them through the wall. However, this could still involve some level of disruption to the tiling.