I glance at the Classes page every week to see if there's any update. It has detailed info for only Cleric, Shaman, and Rogue. The Classes page lists 5 aspects for class info: Group Role, Armor, Weaponry, Ability Arsenal, and Iconic Ability. Surely at least some of those for some classes are finalized?
I know the answer is "We'll reveal the other classes when they're ready," but, like everyone else, I'm just looking forward to any additional info!
You should check out https://pantheonriseofthefallen.gamepedia.com/Pantheon:_Rise_of_the_Fallen_Wiki, it has more information on the classes and is better kept up to date than the front website at the moment.
Hopefully once they get the new forums and website up and running it will be kept up to date better, but until then the wiki is your friend. :)
New class/race information is slowly released as parts of major announcements.
It's not like they went into day 1 of development with 100% complete design docs on each race and class. That type of information changes over time, much like gameplay features.
Until full release I would consider all names, abilities and even party roles as placeholders. The freedom to change a design 1st draft to a 2nd draft is a key part of the development and testing of a game. For a game on a limited development budget it is even more important to be able to scale the retail product based what can be completed in a high quality manner before the money runs out.