Adobe is ending support of PS Type 1 fonts in a few years. But in the document properties of PDF files Acrobats shows the included fonts as Type 1, even if you've only used OTF in your document.That is quite confusing.
Oftentimes a work in progress is checked only via PDFs, and it's impossible to know whether the correct type of font has been used or not.
I can't see this being very difficult to implement, since there's already a special way to show when a TTF font has been used.