Yes. Even the iPad Air 1 LCD is compatible with both models too. Brightness varies though I don’t remember off the top of my head which one had a brighter LCD.
Quoting myself no this is not true. Only iPad Air 1 and 5th gen are compatible displays with each other.
iPad 6 requires the same model LCD can’t use other LCDs from 5th gen or Air 1. Must be 6th gen only. This is based off any seller other than iFixit listing it as 6th gen (e.g a1893 only).
Unless iFixit confirm and guarantee it’s iPad 5th gen / 6th gen hybrid LCD (somehow) works on the iPad 6 then I will say otherwise.