Caudillo
If by the GPUs you mean the 146 fleet, well Willie took the axe to them at EI (and did his best to shaft the crews too). I guess it depends how much pressure BA will be under to maintain a presence at LCY - and a few Steep Approach modded 318s could be the answer to that although you can't get IAE ones and that's what BA likes these days.
An interesting tack would be re-equip CX with Embraer 175/190s to replace the 146/RJ on non-steep/short routes (with the assistance of a trade-in of the 145 and/or conversion of the 17 options). Air Canada mainline have just taken some 175s and the early noises seem to be favourable.
Meanwhile AC Jazz is pushing further and further south with their CRJ705s - if Willie was feeling combative this could be his CX model - replace UK/near Europe 320/737 with fast RJs.
Sector lengths for Eurofleet 757s/320s/737s would get longer and longer to replace the Eurofleet 767s. 4 SH 767s are being converted to longhaul and Rod E has said "I would not be surprised if we dusk some more, which will give us some long haul growth."