This also applies to the new method `getValidationFailuresArray`, what's the reason for this?

I mean there is no value to the model having this method. It doesn't reflect anything new, but transforms `ConstraintViolationListInterface` into an `array`. Which imho should be a utility which gets any `ConstraintViolationListInterface` regardless from its origin. This utility could then also be used e.g. by a view helper to filter by a specific field etc.