Will older pdf files need to be rewritten with open type if they have postscript type faces?

You're fine. The whole Type 1 Go Bye Bye thing is very confusing. Postscript Type 1 outlines in a PDF are still very valid and will always be. What IS changing is that there will no longer be support for the old font file structure of a Type 1 font. e.g. on a Mac, you had to install both a screen font and a printer font;  or; on a PC, you had to install both a PFB and .PFM files (and sometimes .AFM files). This file structure was a necessity in its day but verrrry old school, wasn't cross-platform compatible, and hasn't been necessary to be this way for over 20 years. OTF, of course, is the solution to this problem by combining everything into one file (that is cross-platform compatible), with a PDF-style compression to reduce the file sizes, but also with the bonus of adding all the extra glyphs and modern encoding needed these days. But in practical terms, an OTF CFF font is a Postscript Type 1 outline that is compressed (CFF = Compact Font Format) using similar-to-PDF-style compression for space saving. Even these will still list as Type 1 in a PDF because that's exactly what they are.