It's a "16G" just like the 20G XTR is a "20G". Meaning, only really in the name. It's a Garrett GT28 center cartridge with Blouch wheels ("16G" compressor) and housings. They can call it what they want (and if it spools like a "16G" then it's a fitting name). I'm not knocking it (or Blouch's naming), it's just not really a traditional "16G", so it's not too surprising it makes such good power.
The power does look good though. I seems it could be an excellent turbo for a 2.0L. The only concerning thing from the plots you posted is the spool. Peak torque at 4,700RPM's seems quite slow for a turbo this size. Do you have a boost plot? Or do you know what RPM it hits 20psi at on the street?