When will Riot create AP tank items?

There are no AP items designed for AP scaling tanks(like Amumu, Sejuani, Nautilus, Zac...) in this game, only mage/assassin-designed items like RoA, Rylai, Liandry/Abyssal etc... that can work on tanks but they are expensive(often 3k+). Even supports have their own AP items.

If you are an AD tank you have tons of great options for offensive items that fit with your gameplay because they were designed for you: They give tankyness, damage and some of them also mobility/cdr.

Whereas the only AP items that really fit with tanks' gameplay are: but they only give damage.

is overkill as most tanks already have decent CC, have no particular interaction wih tanks exept it gives good stats. All other items don't give enough defensive stats to be bought by a tank.

I'd prefer items giving few AP and decent defensive stats+ a passive/active that interacts with AP tanks, like support items focus on support's job: helping your team and they give a few AP because supports scales on.

For exemple: 50AP, 70 armor, 10% cdr, passive: hitting an ennemy with a spell increases your movement speed by 5% for 4s(max 20%).

This exemple is not meant to be balanced, that's just to show what could be done instead of actual items.