With the takeover and closing of BD by IAG, there is no shortage of slots at LHR for BA , so let‘s knock that particular bit of misinformation on the head.
Of course it's about the LHR slots. This is IAG setting itself up in anticipation of a "NO" decision on LHR R3. If or when that happens there is no way IAG is going to continue running 21 plus flights a day on LHR-DUB ad infinitum.
At some point in the future at least some of those BA operated LHR-DUB slots will be quietly reallocated to other routes, with perhaps larger aircraft operating the remaining dozen or more frequencies. IAG may not be admitting that now until the deal is all done and dusted, and it may not happen for another five or ten years, but it will happen...
All the current media hype is about growing DUB as a North Atlantic hub for IAG with connections from all over the UK, new routes, more jobs etc etc. But slots at LHR, and the future potential of those 8 or so pairs of BA operated slots, are very much in IAG's sights as well.