That would be the only reasonable explanation I could think of.
Here is a crude example to illustrate how cancel-rebook pours points into an account. Forget the credit pool. For this discussion, it is a red herring.
Start with 2 million points, book 1 bedroom for 180k + four 3 BR Pres for 1.54M + 280k leftover points = 2 million
Run cancel-rebook-cancel-upgrade
You now have 4 Presidentials @90k = 360k + 1.64M points to run again
Book 1 bedroom for 180k + three 3 BR Pres for 1.155M + 305k leftover points = 1.64M points
Run cancel-rebook-cancel-upgrade
You now have 7 Presidentials @90k = 630k + 1.37M points to run again
Book 1 bedroom for 180k + three 3 BR Pres for 1.155M + 35k leftover points = 1.37M points
Run cancel-rebook-cancel-upgrade
You now have 10 Presidentials @90k = 900k + 1.1M points to run again
Book 1 bedroom for 180k + two 3 BR Pres for 770k + 150k leftover points = 1.1M points
Run cancel-rebook-cancel-upgrade
You now have 12 Presidentials @90k = 1.08M + 920k points to run again
Book 1 bedroom for 180k + one 3 BR Pres for 385k + 355k leftover points = 920k points
Run cancel-rebook-cancel-upgrade
You now have 13 Presidentials @90k = 1.17M + 830k points to run again
Book 1 bedroom for 180k + one 3 BR Pres for 385k + 265k leftover points = 830k points
Run cancel-rebook-cancel-upgrade
You now have 14 Presidentials @90k = 1.26M + 740k points to run again
Book 1 bedroom for 180k + one 3 BR Pres for 385k + 175k leftover points = 740k points
Run cancel-rebook-cancel-upgrade
You now have 15 Presidentials @90k = 1.35M + 650k points to run again
Book 1 bedroom for 180k + one 3 BR Pres for 385k + 85k leftover points = 650k points
Run cancel-rebook-cancel-upgrade
You now have 16 Presidentials @90k = 1.44M + 560k points to run again
Book 1 bedroom for 180k and there are 380k left – 5k short of reserving another Presidential
So 2 million points reserved 16 Presidential units for 1.44M points + 1 BR for 180k + 380k points left.
16 Presidentials has a value of 6.16M of reservations (in an account that should have only 2 million) + 180k 1BR + 380k leftover points = 6.72 million points.
This elaborate cancel-rebook scheme generated an extra 4.72 million points for this account. A more refined process using more efficient units could easily generate 6 million or more.
It seems some such accounts have been frozen, whether Wyndham was looking for them or not. There are other accounts where Wyndham might have swept up the account, but the credit pooling or other explanation might be the reason. It will be a mess to sort out. Look how complicated this account would be, and it is only at one resort, not scatted across unit sizes in multiple resorts.