What are you talking about? Several months? The last stable update has been uploaded to Sourceforge at 2018-11-07 - almost exactly 2 months ago. Did you check the stable MIUI 10 ROM thread? I presume you didn't - in the 10.x stable ROM's thread ingbrzy announced the following:
"MIUI 10.2 stable will be released for Android 6.0/7.0 devices"
Check the changelogs' dates, stable is released in 2..3 months periods - it' not strange. If there are problems with the code I don't mind if they don't release it.. that's why there's a beta/dev path..