I don't think that is true (maybe I missed something from their page?), which means they will always have the incentive to make more premium content in order to generate more revenue, especially if they need it to cover the expenses.
Whether overly abundant donations are misallocated is a completely orthogonal issue.
Note that I’m not saying we are entitled to anything; but slapping the MDN brand on a premium subscription service does tarnish the original brand a little.
Is my understanding incorrect?
Wikipedia misallocating funds does tarnish the original brand a lot, especially when most people that contribute content are doing it for free.
Which has nothing to do the donation model.
Wikimedia can pay full time content writers if they want to.
Mozilla can also use the subscription income to pay CEO comp if they want to.
Allocation of funds has close to nothing to do with the acquisition of funds, unless the acquisition comes with a specific mandate, which neither Wikipedia donations nor the subscription service here has.