Sleep study indicates apnea

My 8 year old ADHDer had a sleep study that indicates central, obstructive and mixed sleep apnea and hypopnea. Dr recommends removal of tonsils and adenoids which is how we intend on proceeding.

My question is; if this surgery does eliminate the apnea and he is getting more restful sleep, will his ADHD symptoms improve? He is combination type, inattentive and hyperactive (on stimulant meds for a little over a year)

Will he be able to have more control over emotional regulation?

My hopes are so high that this surgery- and thus improved sleep- will be life changing, improving all aspects of his life.

Any one have first hand experience in this situation?