The FinCEN guidance absolutely, categorically did not say that Bitcoin was money. Hence the gravity of this development.
This is a very important point likely lost in the telephone game of people generalizing statement and removing context after the FinCEN announcement.
FinCEN by virtue of the BSA have very wide (I would argue maybe too wide) authority to regulate far more than just transactions involving "money". A simplified, definition (which shouldn't be relied upon for legal purposes) is that FinCEN regulates the transfer of value. FinCEN never said Bitcoin is money (and never said it wasn't), they didn't even say it was "currency". Instead in the guidance they relegated it to the term "virtual currency", which doesn't exist in any relevant statute. FinCEN's guidance was that the exchange of virtual currencies for real currencies (and vice versa) as well as the exchange of one virtual currency for another (aka "being an exchanger") constitutes money transfer. Depsite the word money in the name, money transfers involve a lot more than just money.
FinCEN's regulations define the term "money transmitter" as a person that provides money transmission services, or any other person engaged in the transfer of funds. The term "money transmission services" means "the acceptance of currency, funds, or other value that substitutes for currency from one person and the transmission of currency, funds, or other value that substitutes for currency to another location or person by any means. The definition of a money transmitter does not differentiate between real currencies and convertible virtual currencies. Accepting and transmitting anything of value that substitutes for currency makes a person a money transmitter under the regulations implementing the BSA.
As best one could make the statement that FinCEN said "Bitcoin is a value that substitutes for currency". As you point out this was incorrectly simplified to "Bitcoin is money" but was never correct until today.