I think Williams' decision to lower tuition is shocking. That is not a school that would have trouble attracting students at full price. And the cost of attending private universities hasn't had any relation to inflation or anything else in the real world (except what the market will bear) for a long while, if it ever did. Williams should be able to easily afford the cut though--and this may put (some) pressure on other wealthy, super-HA institutions to do the same.
Unfortunately, not many schools are going to be able to follow Williams' lead. Public schools have seen declines in state funding for at least a couple of decades (while spending generally has gone up). ( https://www.chronicle.com/interactives/statesupport ) Most private schools rely on tuition for operating funds--only a relative few have large endowments. And every school has been thinking about the fact that the number of college-aged Americans is set to decline significantly in the next few years.
I don't think Harvard and other big names will need to change their model much, if at all. But there does seem to be some kind of shake out coming among U.S. schools. Many were predicting that pre-C19; the pandemic is just going to add to the stresses on colleges.