Thanks for reaching out. To answer your question, yes this change was intentional and began in Vectorworks 2018.
Since then, we’ve completely shifted from using the “Material Take Off” or “MTO” record, that use to display in the “Data” pane in the Resource Manager (that you have circled in your screen image), to a more integrated and complete record that is captured using IFC.
Most of the same data that was capture in the MTO record has been moved over to the new record plus the addition of IFC entity/Pset data, OmniClass/Masterformat, Uniclass2015, COBie, and manufacturer-specific data (such as SKU and product description). This data now appears in the Object Info. Palette under the “Data” tab as an IFC record as well as under “IFC Data…” which you can access by right-clicking on the object in the Resource Manager (see attached images/images below - "OIP" + "RM_IFC Data").
Fortunately, this record is completely compatible with Data Tags. I’m not sure what data you want to displayed in your Data Tag, but if you use “IFC Entity” as the Data Source when “defining” your tag, you should be able to display any of the default data in our Vectorworks models in your tag and onto your drawing (see attached image/image below - "Data Tag Definition").
I hope that this help!