The shareholdings of employees by virtue of current or past employment are in most cases relatively minor - it's the pension funds and general-investor-focussed fund managers that company secretaries will worry about.
If company secretaries make known their intended policy to the likes of FTSE, MSCI and S&P, it is likely that these airlines may drop out of pan-European or global fund indices and the non-EU big passive tracker fund managers will then end up being forced into selling their holding in these airlines anyway