It's great improvement that since ArcGIS Pro 2.9, project options settings on the display tab (which includes antialiasing settings) are honored when exporting map (https://community.esri.com/t5/arcgis-pro-ideas/control-antialiasing-for-export-to-tiff-pdf-in/idi-p/1019601), as was suggested in the idea "Control antialiasing for export to tiff/pdf in arcpy.mp".
However, when using the tool PDF To TIFF (using PDF which was previously correctly generated in ArcGIS Pro), there is antialiasing always enabled, regardless to the project options settings.
It's very important for us to have the possibility to turn off antialiasing in the PDF To TIFF tool, since we need to have only discrete colours in the resulting tiff (which is then used for further processing).
Thanks,
Jakub