Xiaomi VP Lu Weibing is expecting the first LPDDR5 smartphones to hit the market in Q1 2020. Weibing is probably hinting at the Redmi K30 5G that is supposed to launch in January next year, since this model will also be powered by the new Snapdragon 765G SoC that is compatible with the new memory standard.
https://www.notebookcheck.net/Xiaomi-to-introduce-LPDDR5-handhelds-in-Q1-2020-K30-5G-first-in-line.447115.0.html