Having flown in a previous career and now working at a centre as opposed to an approach unit, although I did my 15 hours flight fam, I honestly don't think the 15 hours, or even PPL would be of that much benefit to someone who had never flown before (though it was a good 2 weeks away from college).
Flying a PA28 or C150 from a sleepy airfield is a world away from flying a modern glass cockpit aircraft from a busy commercial airport.
Having said that, at the very few airports that NATS provides a service where light aircraft circuits still happen, I think some sort of famil would be beneficial.
For larger airports and area units, more fam flights would, IMHO, be far more beneficial.
As for the 'team building' week - the company that NATS used to employ was staffed mainly by ex mil bods. The 'team building' exercises where taken straight from the military and were actually more to do with leadership than team building...the real team building happened in the bar of an evening... Easy money for the company that supplied their services, wasted money for NATS.