Achievements from Halo Wars: Definitive Edition still aren't included in the total halo gamerscore on your waypoint profile. I looked up a thread that was made on January 6, 2017 where another user noted this issue and was given the following response
Zappy180 wrote:As far as I know, achievements earned from Halo Wars DE don't contribute to your overall Halo gamerscore on your profile.
Does anyone know if this will be getting updated to include Halo Wars DE achievements at any point?
I'm just wondering if this issue is still on the radar to be updated.stckrboy wrote:Achievements and achievement score will likely be updated once the game officially launches next month