It is fair to say LHR is full and any new entrant must obtain slots from a current carrier
BA has no slot shortage, recent new routes domestic , shorthaul, mid haul and longhaul PLUS currently lease slots toother airlines
BA do need to wait for their new aircraft to switch some of their less profitable slots eg DUB to other routes, probably Longhaul .
No commercial sense in buying more slots in current climate when they already have a surplus
They barely have enough slots to compete with its European rivals even after buying BMI (only that has allowed BA to launch more routes), what makes the problem even worse is that LHR AND LGW are full and cannot be expanded
I mean look at it this way, BA currently has 52.5% of the slots at LHR (Along with 20% at LGW), on the other hand Lufthansa has 70% of the slots at FRA and even more so in MUC and Air France-KLM has 60% of the slots at CDG and AMS, all of which can (and do) handle more flights than LHR, that gives them a vast advantage (and I haven’t even got to the other hubs, such as LH’s hubs at ZRH for example)
That is why BA European rivals have more extensive networks to South America (which is taking market share from BA’s sister airline IB), China and Africa than BA, while BA has the advantage (just…) in terms of flights to India and America, LH (with help from UA) is now not that far behind in both cases
So they really need to buy as many slots at LHR + LGW + LCY as legally possible (and I mean really push it to the absolute limit) to prevent BA from falling further behind and keeping up its rivals in Europe, North America and the Middle East