Apple first introduced FaceID on the iPhone X in 2017. Since then, the facial recognition tech has been added to one of the iPad as well. Last year, the company redesigned the iPad Pro by giving it a similar treatment as the iPhone by ditching the bezels and the home button in favour of FaceID and a software based gesture navigation system.

FaceID was also added to a new budget version of the Apple phone, the iPhone XR. The tech appears to be spreading to more and more Apple devices. So now the question is when will FaceID be added to all the iPads as the company is still using TouchID on the iPad Air and the recently released 10.2” iPad.
iPad Air could get FaceID before the $329 iPad
The $329 iPad is a budget tablet which does not sport the best of the best internals but its an iPad after all, and it would make sense for Apple to use FaceID on all its devices. The company is probably already working on bringing FaceID to more of its devices including the budget oriented devices.
It takes time for new technology to turn affordable as when the demand grows, it becomes easier to manufacture the product on a large scale, hence reducing the cost of a single piece. We expect the same to happen with FaceID as Apple bring the facial recognition tech to more and more of its products, it could soon be found on the iPad Air.
Its difficult to say whether the $329 iPad could also receive the FaceID update as the product is already priced extremely low. Sure, it sports old internals but the company needs to return a profit and FaceID is not exactly cheap but hey, TouchID turned cheap over time and the same could happen with FaceID as well.
In case of the $329 iPad, it may take more than a year for FaceID to make an appearance.