Most of the comments are saying that this is only about the magnetic pole wandering.

However, it also says

'the “entire solid Earth reorients to restore this alignment,” according to the paper. But the core and climate belts remain fixed,'

So this is indeed about physical Earth tipping, and it seems that it's trying to say that it happens during times of "polar wander".

Regardless of what it is saying it is so badly written it has no place in public discourse.