I can only speak to WDW but the rates are significantly higher in October here also.If the prices are insane it’s more likely due to a conference at ACC than Disneyland. One big event there sends the entire area’s supply and demand all out of whack.
We have trips booked the first week in October and the first week in December and the October room rates were higher from the get go.
Perhaps its the interest in Fall and the Halloween events???