There's a surprising twist at the end of the 'synchronized global growth' story

We keep hearing about “synchronized global growth” which has supported stocks over the past two years and also as a case for equities going forward. Based on a recent note from Fidelity Viewpoints it seems the synchronized expansion story still holds though global growth may be peaking. Fidelity points out the US "is experiencing a mature expansion, with mid-cycle dynamics and some hints of late-cycle trends."