Can I decrease salty flavor after brining a turkey?
If you make good turkey gravy with little or no salt, and simmer and store the turkey in that, I think that's the best you can do. The hard part is making good gravy with low enough salt, since low salt turkey flavor is hard to find.

You might consider a bit of an odd idea. You can make milk gravy with ground turkey, much like what in the Army we called SOS. Use the bare minimum of salt.

Serving the turkey with that, perhaps in an open-faced sandwich, could be good. Consider that with slightly under-seasoned mashed potatoes.

Good Luck! Let us know what you end up doing and your results.