The iPad Air2 does not support iPadOS16 or later. At present, the most recent version of iPadOS supported by the iPad Air2 is iPadOS 15.7.8.
Whether of not the Air2 will receive a further update will not be known outside of Apple until (or if) it is released. That said, where the current major version receives a security update, history demonstrates that an update for the preceding major version may follow some days behind.
The iPad Air2 is well within its "twilight" period of update support. For security-critical applications, it may now be advisable to at least consider replacement with a newer model, capable of running iPadOS16/17, within the coming year - if not sooner.