The devs have never agreed to any licencing deal that grants exclusive content and have avoided doing so as a matter of principle. If they have indeed produced a custom Rockingham track then it will, sooner or later, end up in the product that we use.
However the version we get may well be a further development, they'll have produced a track to meet a deadline to satisfy the licence agreement, but that does not meen that it is as complete and to the standard they wish it to be before it is released to us.
As for whether the rumour is true or not, I dont much want to speculate - but the old hands have been begging for new environments for some time - and I know that the devs do listen...
...We just get things when it suites them, not us.