Please allow for the rotation of labels for points in ArcGIS Online Feature Layers using a numeric field (or a hard coded value). Similar to what you can do in ArcGIS Pro.
My particular use case: engineering road chainage labels are commonly aligned perpendicular to the a road alignment (and also offset) in drawings and plans. Consistency between web maps and drawings are valuable for AEC users. Just one example here, rotated labels can improve web cartography in many other ways.
Documentation for label rotation in Pro:
Set point label rotation—ArcGIS Pro | Documentation
This was also question from 2020:
https://community.esri.com/t5/arcgis-online-questions/rotating-labels/td-p/627894
Image to describe idea: