I have yet to see a truck fixed (on forums/ or youtube) that didn't have the sound come back. Some went much longer than others, but my truck was making it again within a week. There have been several engines replaced due to this issue as when the dealers dug deeper they found worn main bearings, cam caps and other tolerances that were way out. The thread on F-150 Forum has a few but it takes a lot of reading.From the many pages that I have read about this topic it seems like the replacement chain doesn't always fix the issue.
Good luck with your dealer.