Digital Foundry says the dev unit for the OLED Switch comes with 8GB of RAM, while the dev unit for the regular Switch came with 6GB. All retail units still with 4GB. :
Did anyone ever tried a RAM upgrade on the switch? | GBAtemp.net - The Independent Video Game Community
19-Current Ram 2500/3500 SDHQ Built Complete Switch-Pros SP-9100 Kit
2PCS Original NEW EMMC 64GB 32GB RAM Replacement Part For Nintend Switch Game Controller 32GB Memory Storage Module - AliExpress