Someone else can jump in if they know more...and if so, please do, as I'd love more info....but...
Leaseholds are a timeshare in which you own part of a unit for a fixed number of years.
Except for GCV (where DVD can resell any contract they ROFR within a day, with the existing number of points), I assume that Disney is trying to arrange multiple ROFRs in the same unit. All sales are deeded to a specific unit. If DVD buys back 150 points in unit 1A and 150 points in unit 1B and 150 points in unit 1C, they can only sell those in chucks of 150 (or less) tied to each of the units, but if they buy back 150 + 150 + 150 all in unit 1A, they can slice and chop those 450 points any way they like. So I suspect (but again, don't know) what's happening is that DVD has a target list of units that it wants to build point inventory within as that allows them greater flexibility for the person who wants to buy 50 and the person who wants to buy 500. If I had to take another guess, I'd say it's easier to do this in the larger units, as there's a larger pool of possible points there. I'm sure someone has done the math, but just to eyeball this, (and as GFV is presently a ROFR target), there's somewhere "around" 11k to 12k points attached to a studio at GFV per year and there's somewhere around 26k or 27k attached to a two bedroom per year. Simply, on average, there's a far, far better chance of building a combined ROFR bank of resale points in a two bedroom unit than in a studio. Again, these are all educated guesses with some of the math eyeballed, but I sorta suspect that's what's actually going on.