My totally stock 1986 Miyata 710 has Dia Compe 400 brakes with aero levers (bummer because I was thinking of lending it to my daughter do ride the California Eroica). All the Miyata bikes in the 1986 catalog that were running other brake brands had non-aero levers. The 1985 and earlier Miyata catalogs don't have any bikes with aero levers, including those running Dia Compe 400 brakes, so that is probably the cut off for Dia Compe.
On the other hand, Shimano 600 AX aero levers came out in 1981 according to Velo Base.