Shadowverse

Well, either Kazakus was initially conceived as a full-fledged replacement for Reno (but they didn't have enough strength), or something will definitely happen. Let's say they won't introduce any more cards to support the Old Gods, even though the situation is largely the same.

an official statement from Blizzard that they are not going to release cards with a mechanic similar to Reno anytime soon

It's roughly like the statement in which they guaranteed that no card would leave the Classic set and that this set would be eternal.