It takes 2 to tango, Apple would not have done this without a gun at their heads. iOS maps were clearly behind the state of the art and it was, for some reason, impossible to modernise them.

The gossip is that Google requested unacceptable licensing changes. Whatever the truth is, this situation is due to Apple and Google being unable to reach an agreement. Apple can and will recover this situation within a few months and, if Google dropped them into this situation, they will be looking for an opportunity to exact revenge.