KLM doesn't codeshare on the Belfast route, at least it doesn't appear as an option on either the UK or the Irish KLM website. It's also worth noting that you can't book at KL coded flight from Ireland to Amsterdam unless you're making a connection.
I think what would be more likely would the EI-KL codeshare disappear and be replaced with either a service operated by CityJet or KLM Cityhopper once they get some reliable aircraft.
Unless AFKL is thinking of bidding for EI, but if they are then it's been kept a secret. How much of EI is owned by FR now?