Since reverse osmosis reduces boiling time, the sugars in the sap will have less time to caramelize. This can result in lighter colored syrup compared to sap that has been boiled for a much longer time. However, the data shows that the actual composition of the finished syrup is not changed in any significant way.1
1) van den Berg, A.K. Perkins, T.D. and Isselhardt, M.L. (2019) Composition and Properties of Maple Sap, Concentrate, and Permeate. Agricultural Sciences, 10, 32-45.