mpu-60x0 external clock capability

Hello everyone!
In my project I use MPU-60x0 giro and accel signals with strict synchronization with other sensors. To achieve that I am using external clock for MPU-60x0.
Now a mpu-60x0 have a NRND status and I want to substitute it by a new integrated circuit but cannot find any other ICs with external reference clock capability. And not only Invensense has no such ICs, but ST and Bosch too.
So, why Invensense remove this feature from new products? Does Invensense plan to discontinue to manufacture a MPU-60x0?
Thanks.