Given the changes of Re:build, one has to notice that hidden Classes were spread evenly among the 5 Class trees.
Swordsman has Nak Muay, Archer Appraiser, Cleric Miko, Wizard Rune Caster and Scout Shinobi.
Chaplain got turned into a normal Class, balancing out the hidden Classes per tree to 1.
Aside that fact, advancement-related quests like Exorcist,Retiarius,Piper,Onmyouji,etc. were removed and we’re having Class unlocking vouchers via Popolion Point Shop and Leticias Cube make me wonder if IMC is actually abandoning the whole hidden Class system slowly but steadily.
If we’re talking about the 80 Classes which were the base target at the beginning, if we count the current build limit for Swordsman,Cleric and Wizard, we’re at 16 advancement Classes.
Once the Class trees of Scout and Archer are filled up to 16,too, we’ll have 5 * 16 = 80 Classes, which is the initial target of IMC.
Of course, MMORPGs live from continuously adding new content,including new Classes, so an improvement of that limit might be not so far away(2020 maybe?), but with the current ultra-casual gamechanges, I can’t imagine any new Classes added as “hidden Classes”.
Maybe the whole hidden Class-system will be reworked into a Master-Circle system,as they also abandoned the idea of producing more 3rd Circle costumes inbetween, which could hint at the possibility that these costumes will be released as Master costumes in the future.