The name 70/30 for the PG/VG percentage, or 100% VG / all VG just refer to the base materials. They have nothing to do with with the final mix percentage and do not apply to the finished product.
For example a "100% VG" eliquid might be (for example) 77.6% glycerol of unknown origin (so it might be VG but then again it might not), 10% water (distilled or deionised), 10% flavourings (including the excipients, which in some cases might be PG but are often ethanol), and 2.4% nicotine. So even a VG-only refill could conceivably be less than 70% VG (as some makers put a lot of flavours in) and it might even have some PG in it.
All these names are just a convenience and a guide, they mean nothing in reality. (Unless the vendor gives the final mix percentages of course.)