Now where does that traffic come from certainly not entirely organic growth imho, much would be sucked in from other middle sized airports and Gatwick is that in the national interest?
There's no guarantee that the extra slots available will generate any new routes for either regional or global connectivity.
How many new routes would EZY bring? LHR could just become the regional airport for West London, Thames Valley etc, saving them the tedious trek to LGW, LTN or STN for their short breaks.