I understand your point, high budget digital only games, right?
I think a game that fits your pattern is WipeOut HD, this game was certainly not low budget or indie. Yet (at first) it released digitally only and for only £15, Fury expansion added to this digital package only. The game holds more content than many full priced retail releases at the fraction of the cost. So it's not F2P but that doesn't mean it didn;t have a high budget.
There is still a stigma on digital titles only though, the competition in the market can mean prices are still not low enough while in retail competition lowers games costs contantly. In the case of the 2 F2P games in question, it's a matter of whether their content is worth playing at all, let alone paying for. Tekken Revolution is best to compare to KI, it would have had the budget and backing of the Tekken development team and for what I know of it, it is succeeding. KI could easily follow.
The digital separation though will never close for home consoles until official stores get their pricing in line with retail shops.
Hmm, pie.
