Who said anything about politics? It would be just a team move, happens all the time - if the guy is liked, his minions might follow him wherever he's going to land.This is pure treacle, and Renaissance will be just fine. The HF and bank desk trading environment has become so condensed and rarified that the idea of mass defections from a highly successful HF over of all stupid things politics is IMHO bullshit.
PS. Successful stat-arb/HF PMs seem to be in demand, at least in my recent experience.