Is there absolutely nothing that Whittaker and Ferguson can do to become the official champion?

In terms of the level of competition they have consistently beaten, and the 'champion's' inactivity in their respective divisions, I can't help but feel that Whittaker and Ferguson should have fought for the title long ago.

But the UFC seems more than content to have both GSP and McGregor clogging up the most stacked divisions. And it seems very likely both Whittaker and Ferguson won't get a title-shot for a very very long ass time, through absolutely no fault of their own.

So, my question is, what exactly does it take for them to receive the title-shot, if consistently beating the top contenders doesn't get you one?

They will eventually. It may take another year or so.