Your contract will not automatically change over to a Swissport contract after 2 years (I'm still on an Aviance contract 4 years after they dissapeared).
The company can however deem that your job no longer exist, for example, what Menzies did with the Ex-Servisair Ramp Team leadrers who TUPE'd over with the BA contract at MAN as Menzies stated they do not have that posistion within Menzies.
For the most part, the people who actually do the job i.e Pax services, Dispatch, Ramp will in the main be O.K (someone has to do the work). Only where there is a duplication of jobs, at stations where both companies exist i.e MAN, LGW and STN, will there be a reduction of staff. A good example is management. Having been in a company taken over and being in a company taking over another since 2007 at MAN, without exception, all the management personell from the company being taken over have been shown the door.