I just saw this on the Accademia's website but can't see that it's been communicated on the Firenzecard website.
http://www.galleriaaccademiafirenze.beniculturali.it/eventi/1/131/notice-firenze-card-possessors/
We inform our kind visitors that from March 1st 2019 priority access
to the Galleria dell'Accademia of Florence for Firenze Card possessors
will not be permitted. For further information, please contact
055.055.
They do not explain the details so I'm unsure if you have to stand in the regular ticket line or in one for people who already have tickets and there's just no dedicated Firenzecard entrance. I'm thinking it's the latter but... Anyway, a heads-up that something is different! Hopefully there'll be more formal info provided on this change soon.
Editing to add: if anyone is up for calling the museum, that'd be great too.