What is happening to the ADC position?

In the last week I've been playing there has been an increase of mages and assassins on the bottom row.....so my question would be is the position dying and if so why?

I really loved the challenge and feeling of beating a ranged attacker when they could just pepper me from afar and kill me......now that they are gone I am going through a learning curve again for the new changes.

So I suppose it breaks into 2 parts: where's the ADC and/or is this a temporary change?

May the stars guide you