All 2020 iPad Pro models feature 6GB of RAM, same U1 chip as iPhone 11 - 9to5Mac
Apple iPad Pro 11 2021 A2459 Space Gray 256GB 8GB RAM Gsm Smart Tablet Apple M1 11.0 inches 5G The tablet comes with a 11.00-inch touchscreen display with a resolution of 2388x1668
New iPad Pro comes with 4GB of RAM, 1TB version may come with 6GB | AppleInsider
Apple iPad Pro 12.9 (2020) - Full tablet specifications