He had "professional attire" as costumes in past games as well,you might want to check them out, as they blow this one out of the water.mk1 one Is probably the worst rendition of his suit/tux costumes.
You bring up a seperate issues though,johnny cage as you say it looking out of place if he had his traditional main costume type.
Normally there should never be a case in a mortal kombat game that johnny having his standard outfit type with the chest tattoo,gold cage belt,blue track pants etc looks out of place.And thats because they changed the univers and the tone of the game so much,its like a marvel super hero movie,with this strange draw to realism and realms essentially being places on earth instead on interdeminsional places of their own.
Johhnys DA/armageddon default is peak johnny,a skin like that with modern graphics would easily be his greatest look ever.The only thing i would change on it is instead of the lion head belt,id have it be the cage belt.
Its just got all the elements right,the glasses the hair,him being jacked out of this world,the hand wraps etc. Fitting to what johnny cage is,or well used to be as they made him into a bit of class clown too much.
And look at the alt they gave him in mk1,the uol skin,lol its pathetic in both asthetics and desing elements,it looks so terrible and bland with also convaying zero personality that a charcater like johnny should represent.