In principle, yes. Different parties would like to see a process of ensuring that all new entrants start at LGW only but until an agreement is formalised (as far as I know this hasn't happened but I am happy to be corrected) then the company can recruit for EF if it needs to.
Once the transfer agreements for LGW-LHR are in place then the company would have a hard time being able to recruit directly into EF. I wouldn't be surprised if they resorted to using EF temps again - in a similar way to how the WW temps have been utilised.