huh?? what are you talking about??
Shadari-Kai is a race, it have nothing to do with any of the class. in fact in game we see Shadari-Kai black guard..and ranger(?)
Purple Dragon Knight is human, they are special trained knight of Cormyrian army, in dnd 3.5e they have nothing to do with fighter or any of the base class. pdk is a prestige class that open to all race, but lore wise they mostly consist of human.
BladeForged- they are warforged who follow the lord of blade...not all lord of blade's follower are paladin, in game we fight many artificer, rogue, assassin alike...
sun-elf is a race, not a class.. it have nothing to do with cleric. morninglord is a divine caster class, they are not cleric. just like stormlord, war priest, champion of torm...etc are not cleric. their class tree and race tree have been tied together so you do not lose anything iconic about it!
Deep Gnome- again deep gnome is a race, it is not a class combination. sure all gnome favor illusionist, but not all gnome are illusionist..especially not deep gnome!
p.s. whatever they learned in the past are merged into their racial tree.. so nothing ever get forgotten. you can rest assure of that.
edit: i just did a quick check.. deep gnome(svirfneblin) favor class is rogue not wizard....