Even more so, in the case where a DLC drop is delayed, Steam will let developers reschedule it for 3 months later. And if the case is for developers to cancel a DLC, buyers will need to be refunded for the item value.
Steam defined what a season pass is on their platform “Because a Season Pass is effectively a DLC pre-purchase, creating a Season Pass on Steam has many of the considerations and restrictions as outlined in the documentation on pre-purchases. For these reasons, we will not offer a Season Pass except in a few rare cases with partners with which we have a well-established relationship and who have a proven track record on Steam.
On their platform, Steam also added for developers “If you aren’t ready to clearly communicate about the content included in each DLC AND when each DLC will be ready for launch, you shouldn’t offer a Season Pass on Steam.”