According to ITHome, some users are starting to receive the referred update for these old models. The Redmi 5 was released in the end 0f 2017, while the Redmi Note 5 came in March 2018. Worth noting, that this is the Chinese version of Redmi Note 5. In India it was released as Redmi Note 5 Pro. It bears a Snapdragon 636 and was the first Redmi smartphone to ship with a dual-camera setup. The Redmi 5 was released in December 2017 along with the Redmi 5 Plus.
Both models got the MIUI V11.0.1 stable ROM but unfortunately, they’re still based on Android 9 Pie.