Hi,
Change how labels are displayed | ArcGIS Pro documentation
Is this what you are referring to?
Caution:
The following text symbol properties are not used when labeling:
Angle—You can specify the orientation of labels through the label placement properties.
Vertical Alignment—The vertical alignment of labels is always bottom.
Horizontal Alignment (Maplex Label Engine only)—You can specify the horizontal alignment of labels through the placement properties.
In the Help documentation Text symbols | ArcGIS Pro documentation - it mentions "when labeling, you cannot set the vertical alignment; it is set by the label engine. Horizontal alignment can be set when using Standard Label Engine; it cannot be set when using Maplex Label Engine. When using Maplex Label Engine, it is configured using the Stack properties."