I wonder just how much thatch he'll have to get out in years to come.
The surprising answer might be... no thatch. I receive compliments all the time on my lawn. I have lived at the same address for more than 25 years, and have NEVER de-thatched.
The trick is to keep in mind that your lawn is not just grass, it's sort of a small ecosystem. There are good insects, fungi and other microbes that will break down the clippings into useable organic matter and nutrients to feed the grass. Also, some of the insects are beneficials that eat the bad insects, a reason I do not spray with pesticides or herbicides.
I do apply a balanced fertilizer at low rates twice in spring and early summer. I apply lime when needed. I apply fungicide only when I can see a problem (which is very rare). I never water unless we are in an exceptional drought.
Other than that, I just cut it each week, and edge it every three weeks. I leave it slightly taller than usual when I cut (but neat, not shaggy), which helps control weeds, also helps the beneficial insects.