Sorry I wasn't clear with my pronouns (?) - "they" referred to the LPs, not Insight. Meaning that now the LPs (not Insight) have to figure out how to reinvest the capital that was returned.
That's only true if the investment was participating preferred equity (sometimes known as "double-dipping"); if it was convertible preferred equity then it's an either/or scenario (they choose between getting their liquidation preference, or converting to common equity and getting their pro rata %). Insight used to be big on participating prefered so I wouldn't be surprised if you're right, but things may have changed..
It's definitely not a total win - first, the return isn't actually ~50% given the $365M in installment payments and assumed unvested equity; second, your LPs committed capital to your fund expecting a certain IRR over the length of the fund (7 years i'm guessing? 10?). Getting them a low- to mid-double digit IRR over 1 year is nice, but it also means that they now have to spend money figuring out how to redeploy that capital for the next 6 years.