I've searched but not found any review of that specific use case, specifically for an office setting using a projector to display power point type of content. (blog.the-ebook-reader.com)
The study tested 100 participants, and compared 18 point type on a tablet versus a print book or newspaper with large type. (macnn.com)
For example, two career management professionals interviewed for this article pointed to the same Microsoft Word template that displays the person's name in large type, then switches to a tiny, barely legible 8 - point type size for the contact information. (theladders.com)