The surprising move was that White said McGregor would not be required to relinquish his 145-pound title going into the fight, as he had originally said the Irishman would.
Conor McGregor will try to become the first to hold titles in two weight classes simultaneously.
McGregor's title fight with Alvarez will be the main event in Madison Square Garden, as the company puts on a fight card in New York City for the first time ever. The prospect of the bout was subject to much speculation in recent days and comes after Alvarez demanded a fight with McGregor on Twitter last week.
McGregor avenged that defeat with a victory by decision over Diaz at UFC 202, with both men calling for a third meeting shortly afterward. The Irishman will take on Lightweight champion Eddie Alvarez in the main event of the first-ever UFC PPV (Pay-per-view) in NY.
Once wind of Alvarez's challenge got to McGregor, he responded with a simple subliminal tweet.
Ahead of the second McGregor-Diaz bout last August, White stated that McGregor should head back to the featherweight division to defend his title after the rematch with Diaz.
In addition, only Alvarez' title will be up for grabs on November 12, as confirmed by UFC President Dana White on ESPN's SportsCenter. If he wins, he will join Randy Couture and B.J. Penn as the only two-division champions in UFC history.
The full story of the UFC putting this card together should become apparent at an official press conference at Madison Square Garden later today. McGregor is also the current featherweight champion, and according to UFC, he'll be able to keep that belt regardless.
Several other stars are set to compete on the undercard including former champs Chris Weidman, Miesha Tate, Frankie Edgar and Rashad Evans.
Should it happen, featherweight McGregor will be substantially supported by his native Irish community at the iconic arena.
UFC 205 finally has a main event.