Yes and no.
9s and 10s came about due to Demand. And yes, they help with lost sales due to dilution, not True lost sales. There used to be only a handful of 1911 makers and there is a plethora of makers.
That is mostly thanks to the AWB. The 1911 became the go to choice for carry when higher capacity guns were restricted to 10 rounds, so why not get a .45?
If it weren't for the AWB, the average 1911 would look like any other 1911a1, and wouldn't have all the other small quality of life improvements outside custom guns
As for what sells, sorry, but ask any decent sized shop what pistol calibers sell and what doesn't. 9mm sells many times over .45. Both in ammo and in guns.