In ArcMap most of the symbology was based on TrueType fonts.
Pro is a little different and I would like to understand the different and how it works internally.
What happened if you import symbology from ArcMap or create a new symbol based on font.
Does Pro save the font number, if so where can I see it?
Do you have to install new font on all the machines that uses Pro with these symbols?
Does Pro translate it to something else?
nothing is said about substitution, but the supported fonts are listed in the above link and the place they are searched for is also given