Serco may or may not go, but whatever and wherever it happens, unless there are a lot of local staff trained and validated, most of the ex - Serco staff will still be there.
The ATC side of Serco has taken a severe kicking in the last 12 months, and I understand that the board are taking a very close look at what's happening now and what is likely to happen within
the next 5 years with ATC contracting in the UK.
It has been alleged, and I've no proof of this, that the UK operation no long makes money for the company. Fewer regional airport providers want to contract out ATC, and there is much twiddling of thumbs in an office in Hook.
Serco as a multi national company makes serious money, and I'm sure they wouldn't tolerate any loss making operation anywhere within.