upgradeAvailability

Shows if a more current base model is available for use with the specified custom language model.

If false, your custom language model is using the most up-to-date base model.

If true, there is a newer base model available than the one your language model is using.

Note that to update a base model, you must recreate the custom language model using the new base model. Base model upgrades for existing custom language models are not supported.