Mathematically there is no difference to having the charger included and being able to de-select it and save 550$ and not including it and charging 550$. Assuming a base price adjustment. Now if tesla where to continue to sell the UMC after sales at the 860$, though I can't find it at all for after sales, then there would be that 300$ incentive to buy when purchasing. Though as I cannot see what the after sales cost is it makes making that calculation speculative.
So mathematically it may be that but psychologically you may be right in that having the option to deselect it and save 550$ may appeal to more people. (Note that would be with a base price increase of 550$).
Now as there is a difference between the mathematical and the psychological what is a better overall outcome, however you might define that, might be debatable.
Having said that, I probably would have included the charger in my purchase if that was the choice at the time as 550$ seems cheap compared to the alternates. Although maybe I would have looked for a mobile EVSE that could do 3 phase 11kw instead of the 7kw tesla UMC can achieve. But am not sure which decade I might do a road trip that would actually benefit from that.