I'd chalk that up to poor reporting, or reading a press release by the reporter as gospel. FWIW, I was not on the 175 fleet but was told this by some company guys at my old gig. They are mixing up the -175E2 and the mid life upgrades on the -170/175 such as the new wing shape etc while also mentioning the geared turbofans etc. Poorly written and contradictory article.
IIRC, the -175s without this mode are really limited in DEN during summer ops.