According to a Town Of Flower Mound Facebook post, FM 2499 100-800 Block (Grapevine City Limits to Lakeside Pkwy) will revert back to being called International Pkwy. This is the section completed in 1991 that bypasses Grapevine Dam. When it first opened, it was called International Pkwy, and Long Prairie Rd followed the old alignment. The bypass section was re-named Long Prairie Rd during the time that the old alignment still held that name, I believe.
Also, why start the block numbers at the southern city limits? Every other city does N-S / E-W starting at the center of town.
My opinion on this matter: This is stupid. Flower Mound already has two major roads hat change names at a point for no good reason, except historical rural road names. Dixon should be part of Valley Ridge, and Gerault should be part of Morriss.