We found some hints for new classes. This might be nothing but just a translation mistake but I decided to share it.
In some robe sprites of twRO, 2019-12-04 and 2019-12-23 these were discovered.
ABYSS_CHASER (Shadow Chaser)
ARCH_MAGE (Warlock)
BIOLO (Genetic)
CARDINAL (Arch Bishop)
DRAGON_KNIGHT (Rune Knight)
ELEMETAL_MASTER (Sorcerer)
IMPERIAL_GUARD (Royal Guard)
INQUISITOR (Sura)
MEISTER (Mechanic?)
SHADOW_CROSS (Glt. Cross)
TROUBADOUR (Minstrel)
TROUVERE (Wanderer)
WINDHAWK (Ranger)
This is just a vague guess, but we will see in the future.