KLM can't do pre 0630 am departure, nothing to do with parking stands, only the opening hour restrictions, not about 'slots'. I think the suggestion of KLM axing the route is crazy and purely speculation, nothing more.
I cannot comment on there point to point v connecting pax, but ex Dublin they vast majority of pax are onward bound, they don't do a huge amount in point to point.
Didn't they get mega ££££ incentive to launch the route?