Don't wanna burst your bubble, but a negligible petition isn't going to change a giant corporation's business decision.
Moreover, Redmi Note 7 has a Snapdragon 660 SoC, it's ancient and weak by today's standards and not worth the development effort.
Just saying the honest truth here...
I would expect Redmi Note 7 Pro and Mi CC9e to get the Android 11 treatment though, given their significantly newer chipsets, but it still boils down to the corporation's business decision.