Hi Andy, no worries! I read a post from another user who purchased a "new" unit, though I think many dealerships are using the dongle and then after it sits on the shelf in parts for years they are selling them on eBay. Just a wild guess, but I've read your story before.
I don't think it's actually VW spreading any myths however, it's the retailers and forums for the most part.
There is a note on some VW parts sites for the
dongle that says "The soundbox DSP default setting is Golf, GTI, and Golf R MK7 hatchback models. No programming is necessary for these models". The programming isn't MK7 specific either way. There aren't any similar notes on pages for the Helix upgrade though.
I think ECS had a note on the Helix page itself about "Units come programmed for a 4-door golf (57)" in the past, but now their site has a bit more ambiguous but still incorrect note that "Vehicles that are not Mk7 Golf, Mk7 GTI, or Mk7 Golf R will require coding." Again, code 57 is for 4-door Golf, Mk6 or Mk7 and not ONLY Mk7, but that's sort of moot.
I had a link for a PDF of the dongle instructions but I can't seem to find it now, but I remember not seeing any notes there about units being preprogrammed.
FOUND IT:
http://www.volkswagen-accessories.com/en/product-ranges/infotainment/soundsystem.html
This has the manual for the dongle, page 7 is in English. The only note is has for codes is to wait until "00" is shown before inserting the SD card. My theory is that the dongle has some memory and will first flash the last code it programmed, then 00. That is where I believe the myth comes from.