Xiaomi has released a stable build of MIUI 11 for the Redmi 7, but perhaps not the version for which people had hoped. While other devices in the first phase of the MIUI 11 rollout are receiving Android 10-based builds, the Redmi 7 is getting Android 9.0 Pie instead. The same goes for the Redmi 7a and Redmi K20 too.
https://www.notebookcheck.net/Xiaomi-Redmi-7-owners-awake-to-a-surprising-MIUI-11-update.440330.0.html