I think UA’s strategy is to expand the most exEWR or exSFO. So - what hasn’t been mentioned - unless I missed it:

EWR-DUS
EWR-STR
EWR-CGN
EWR-DME
EWR-LED
EWR-OTP
EWR-HEL
EWR-LYS
EWR-BHX

Out of SFO, can’t think of any not already mentioned. Could maybe see an ORD-PRG or ORD-DUS.