The 115 x 115 matrix, or RECAT 2, is based on having the ATC software system set up to manage it, especially much further up the queue.
When I stated similar, I meant the systems currently being worked on by Thales, NATS, or other similar ATC solution.
The whole Brexit thing really screwed up progress at LHR, we were virtually signing contracts to move forward, then poof, 3rd runway BS again.