Agreed, think after this year or maybe 2022, EZY will have to make a decision to either base at BHX or cancel W pattern ops there.
Can’t imagine operating slot constrained AMS aircraft to ALC via BHX would work in normal times, nor best allocation of aircraft/cost. But can imagine EZY believes NL won’t be in the best place for summer holidays this year with the covid rates there so works well in this circumstance.