True Tone functionality after screen replacement

If it's anything like the iPhone, you'll need to transfer the screen serial number to the new display to keep true tone. There are tools out there for iPhones but I'm not sure about iPads. In some cases no tool may be available at the moment and may require you to transfer a soldered on chip(s) from the old display to the new one. If that's the case, you'll need someone that is skilled in micro soldering. This isn't a repair you can or should DIY unfortunately because it requires a lot of special tools like a microscope and hot air station.