I bought the new Samsung 980 Pro 1TB (PCIe 4.0) and put in the Lenovo Yoga Slim 7 (PCIe 3.0), I saw only ~10% decrease in raw performance : r/AMDLaptops
Samsung 980 PRO 1TB PCIe Gen 4 x4 NVMe Gaming Internal Solid State Drive MZ-V8P1T0B/AM - Best Buy