Are you actually CPU bound in anything you do with the 4690K? just seeing performance loss in running baby VM's hosting small servers that 3-4 my buds play on (Ark,Teamspeak,Call of Duty(2007), Arma 3) and well it works beautifully (Hence the 24GB Ram)
But as you say maybe wait and see what the market brings but for the 1440p or 2K+ gaming like Ordinarily_Greater said rather look at a bigger GPU though that's why i asked for your guys opinion as i have fallen so far behind and there is no such thing as future proofing in the PC world .
My main issue was many forums i read said you need a bigger PC and GPU for the larger monitors. that's truly how i came round to looking at upgrade kits rather than GPU's