In terms of aircraft utilisation, dropping ATL does not aid this at first glance.
The 2 B744 will operate a mix of 12 weekly MCO and 2 weekly LAS, with MCO looking like it will increase to 14 weekly once the peak A330 arrives to operate LAS. (Last and this summer MCO ran at 13 weekly in peak summer so 14 weekly is an increase of 1).
1 A330 will run 3 weekly SFO/2 weekly BOS/2 weekly BGI < fully utilised
1 A330 runs 7 weekly ATL < fully utilised
1 A330 arrives in July to run 3 weekly LAS < 4 days of non use.
So, you have 4 aircraft fully utilised and 1 aircraft with 4 gaps.
Now, dropping ATL to 5 weekly would not fit in the 3 weekly LAS nor would it be needed to operate any of the new routes.
If anything, the peak A330 could be used to increase any of the destinations, as last year and this year, the aircraft sits at MAN all day between flights doing nothing.
Given the popularity of ATL, it is not beyond the realms of possibility that the aircraft could run anything up to 4 extra ATL flights making it up to 11 weekly.