The national tour is nowhere near ending. They currently have 3 tours out on the road, unheard of for most productions. By 2021 I can see one of them shutting down, but really all I see is The San Francisco/LA production closing and the other 2 tours continue. They'll be touring for the next decade, at least. Likely longer. Only about 4-5 years ago (if that) Wicked shut down their 2nd national tour, and are still going strong touring today. Hamilton's tour is going absolutely nowhere. I follow Broadway quite closely so while yes, a film distrubution can sometimes contribute to lower sales, Hamilton is just such a different animal.