Well they are being kind of vague, as pg is in the propanediol class
Pg as we know it is usually formed from LPG or natural gas what they are proposing is using the plant based version instead, which usually comes from corn or sugar starch alcohols, it's still glycol just a different source. Only long term use will determine if its a suitable replacement for people with pg sensitivity.
But make no mistake. PD is used in many of the same things as pg it is usually seen as a renewable source version but its in everything from soap to foods just like pg.you'll see many health food places and the like using it as a natural alternative