Meh. That's a fairly dated and simplistic understanding of the concept of the PDW and misses the mark.
The term "PDW" may have been first used by a 1986 NATO RFP, but things have evolved since then to include the efficacy of short barrel 5.56 weapons (or 300 for that matter). The development of SCHV projectiles for that NATO requirement was due to the lack of functional SMG sized weapons in rifle calibers such as 5.56. That's not a problem anymore, but it doesn't mean an SMG-sized 5.56 isn't a PDW. They're very much PDWs, fulfilling the same conceptual use and also the industry using the term PDW in such a manner for 2 decades now.
The only dramatic difference in concept is that with the GWOT and explosion of the high-threat protection details employing PDWs, the PDW has developed a connotation for a concealable low-visibility platform, though it's not strictly necessary by the original NATO concept for use by uniformed military personnel.
Meh. Just another example of why we shouldn't have a PDW forum, because not everyone agrees on the definition and stuff that should go in the PDW thread won't, and stuff that should go in the rifle forum won't. Plenty of examples of people not being able to put shit in the correct threads/sub-forums outside this...we've already got people talking about non-collapsible 16" ARs in the PDW thread and people posting pictures of a SCAR in a Mk18 thread.
All the more reason to just let it all be in the rifle forum.