Norwegian
I have not heard BHX mentioned for/by Norwegian either as a base or routes, in fact there has been no serious new base chatter at all, i think the last new base chatter was around 12 months ago about the now opened BCN/MAD bases.
Some on/off mutterings about Berlin/Rome, i think the latter is now very unlikely with the Easy/FR/Vueling bun fight
If you view EMA & BHX as one airport, at least from a customer perspective then it seems most needs are covered