Strange as that's all I ended up doing too and the symbols in symbology still show up with the wrong characters. I have actually reinstalled the TTF's several times thinking maybe that's what the issue was, but didn't make any difference, even after rebooting.
What years does yours show for your Version of the files? My TTF states it's version 4.1 from Macromedia Fontographer from 2004. But I downloaded a set from another link on the forums here and it didn't make any difference either. Since I can still see them fine in ArcMap that makes me think it can't be the fonts at all or I'd have issues in that (I did just recently get a new computer, so just set up the fonts for ArcMap as well last week without issues.).
I just reinstalled all of them again and tested it out just to see and get the same issue with all the DDV fonts in Pro. The only thing I can think of is there's a newer version out there, but I'm not finding them at all?