Now they just need to replace the IPS screen with an OLED one.
That'd be a terrible decision. The battery life advantage would be negligible (OLED only really saves energy when there's a lot of black on screen), it'd still be a thick device, and you'd risk dealing with inaccurate colors and poor outdoor visibility. That and OLED screens at tablet sizes are still quite expensive.
IPS is color-accurate (ideal for pros) and easier to see outside. There's no reason to switch up until there's a clear advantage.