Are the new Office file type in Studio 2019 still using Microsoft Interops to talk to Office applications?

We are aware that the traditional Office filetypes were depending on MS Office being installed on the computer together with Studio. Is this still true for the current filetypes? We are mainly interested in getting an answer for DOCX, PPTX and XLSX, the binary Office file types are not relevant for us any longer.

If not, would it be possible to open multiple Studio instances to create projects? E.g., we have 10 documents and want to create 10 projects at the same time through the project automation API. With traditional filetypes and using Office Interops this was not possible, but if the new file types were not using Interops, it should work. What is your take on this?

Many thanks!