The nefarious version of this theory
Maybe, but I'm a big fan of Hanlon's Razor, and I think they just screwed up. In most other point-based systems, studios are the last to go. That's partly because most timeshare owners did not buy timeshares to stay in glorified hotel rooms, and DVC owners are a different breed in this way as well as many others. But it is also because the spread between studios and 1BRs is much narrower, at which point stretching points is less interesting than having a little more room and a richer set of in-room amenities. In those systems, studios are arguably
under-pointed, because they last so long vs. the larger condos.
I think I've read that Disney isn't just allowed to balance demand, but that they're actually obligated to do so.
They are, but there may also be limits. DVC resorts have internal (legal) structure in the form of "Units". A Unit is (usually) a collection of co-located rooms in the resort, and are treated as one legal entity. For example, when DVC declares inventory into the conodominium association, it does so Unit-by-Unit. When it sells points, the points are drawn from a specific Unit.
People often say "points can't go up or down year to year at a resort," but what the documents arguably say is that points can't go up or down year to year within a unit. That might not, itself, be a problem, except that Units don't have the same configuration so you can't easily change points allocated to studios vs. larger units,
assuming DVC wants to retain the constraint that lockout and dedicated 2BRs cost the same. I think if they were willing to relax that it could work. And, we've seen them be willing to ignore the (presumed) Unit constraint at SSR by rebalancing between Treehouses and the rest of the resort, where the Treehouses were in their own Units. It's not clear whether doing that was legal or not. Most folks (me included) seem to think that it wasn't.
This isn't the only way to structure a resort. Some other developers use "Undivided Interest" where the entire resort is treated as one legal entity. In a UDI resort, there would be no barrier to rebalancing across room sizes, and one is only bound by the "entire resort can't go up/down" rule. I suspect Disney wanted to avoid UDI so that they could retain rights to unsold inventory in a way unconstrained by the governing documents. IMO that was short-sighted, but I'm not a Mouse House executive, so what do I know?
They could at least get the seasons right
And they've been doing that, by increasing fall and decreasing late spring/summer. They have been doing this slowly out of what I believe is a combination of prudence and the 20% YoY limit in chagnes to nightly point values.
Wyndham is probably the most aggressive
As an aside, there has been a vigorous, years-long "debate" over on TUG around this topic. (I put "debate" in scare quotes because, at this point, it's really just become a mud-flinging exercise). For the most part, Wyndham's various changes don't really impact most rank-and-file owners at all, and most of the wailing and gnashing of teeth has come from people using a substantial chunk of their points in a rental business.
