If a number of things happened first then this may fulfill itself. It would take an effort by existing US Star members to commit on a large scale to JFK, for one. LH is heavily invested in JFK, founding members of Terminal 1 and a large cargo operation and although they may move some of their flights to EWR they won't jump ship completely. US and UA have flirted with JFK in the past but have mostly left it to the other two legacies and Jetblue. Additionally, LH's investment in B6 is an investment they would like a return on, whether it be for B6's connecting pax or just a well-run, profitable airline. Their commitment(insistance IMO) to 2 board members(CEO SwissAir, CFO LH) on B6 BOD's is not a sign of disinterest and admittedly B6 is the only US airline LH has put a stake in.

Would LH have made this investment in B6 now had they not earlier? Not sure.