JetBlue TrueBlue - "Add extras" button - possible "upgrades"?

I'm seeing a new button titled "Add extras" when I look at the "Manage my flights" page on the JetBlue webpage. When I click on it for my flights (right now BOS-LAX or LAX-BOS), it tells me:

"The flights you have selected don't offer any upgrades."

Anyone have more information about this?

I have a feeling that this may be a stand alone purchase of the Even More Speed for those customers that don't purchase the Even More Space, which comes with complimentary Even More Speed Access. The Even More Space upgrade purchase may also be moved under this as well.