The panel itself is not calibrated but the electronic components (boards) that feed the display are. If the same type of panel is replaced (Samsung for another Samsung) they should respond very similarly to the components. If the panels are different (Samsung for an Optonics for example) the panel response could be different. That's why copying values from one set to another does not work very well at times, or at all. Board tolerances are different from tv to tv even within the same model and build. Add different panels to that and it can become a real mess.