they failed to secure slots
That sounds like "standard answer 22", rather than the truth.
SXF has loads of free slots as far as I know.
And when Berlin Tegel closes in 2 years time, all that traffic needs to go to SXF.
If Aer Lingus
really wanted to continue ORK - SXF tis summer they could have.
I too hope they'll bring it back. I know a number of Corkonians living in Berlin.