Can't say that I'm 100% reassured. There actually is no historic correlation between primary turnout and general election turnout. None. The highest turnout in a Democratic primary—before the outlier of 2008—was in 1988. Gov. Michael Dukakis got killed in November. Democratic primary turnout was actually lower in 1992—two million fewer Democrats voted in the primaries that year. The drop in turnout didn’t stop Bill Clinton from winning the general election convincingly.
Turnout data also shows Americans don't vote in primaries because they're excited about November.
No Michigan replay: Clinton wins Ohio Democratic primary by comfortable margin. (3/16/2016)