IMNSHO, there should be dangling plotlines all over the place in a properly-evolving game like Shadowrun - because the writers give the GMs 'X, Y, and Z', and let the GM decide what happened with Y and Z while the devs decide what happens with X. Oh, sure, Y and Z may get developed, but only so far - Act 1-3 is DevWritten, but Acts 4 and 5 are put together at My Table.
And in some cases (the 2057 UCAS Election, Missions results, Prop 23) it gets decided by the fanbase as a whole ...