If you only actually have 8 classes and the other 56 promissed are just some different appearances and buffs added to the same stuff we already played for so many levels and got used to... it will be a really bitter pill to swallow.
Thats not what your fans want.
You promissed a necromancer.
Give us a necromancer.
A summoner with a different skin for his bear and some 10% extra damage here and there, maybe a minor heal bonus for his summons at times, isn't a necromancer class.
You promissed a templar.
Give us a templar.
A cleric with a light-sword animation instead of a whip one and with a 10% damage increase on his spear, isn't a templar.
We don't want reskins plus normal buffs you would and should obviously get while leveling.
We want actual, unique, distinct, characters with abilities and passives which fit our chosen theme, the spirit of what we already chose to be.
I'm sure there are a lot of people out there who will be disappointed by the game eventually simply because they imagined it to be something which wasn't promissed, but this right here

this was promissed.