Spenser, I've published PDF's from SolidWorks 2014 since SP0 shipped and my diameter symbols show up just fine. I use the SolidWorks PDF writer instead of Acrobat, but based on the way those symbols export to other cad applications, they're rendered as vectors before being exported, so Acrobat doesn't have to do any substituting like it might for fonts.
I would start by looking in your Options Dialog, under System Options: File Locations and go down the list of search paths to see if they're referencing SolidWorks 2013 resource folders that no longer exist.
A lot of times, this glitch will show up after imaging your registry with a copy-settings-wizard file from a previous release.
If you do a search on your machine for GTOL.SYM that will give you the root directory where most of your SolidWorks paths should point.