That's essentially what I think will happen as well. Steve's body will gradually begin to replenish the super soldier serum and he'll go back to the Steve we all know and love. It's just going to be a while. I thought it would be after Secret Wars, but with the release All New! All Different! Avengers which will be after Secret Wars, Falcon is still Cap. So while it's possible that he still could and be like Commander Rogers, it would then pretty much be Brubaker's run all over again. But I'm pretty sure he'll get it by the time Captain America: Civil War comes around.