See also commit 5cd5f77 “Don't allow promises created with `delay/name` as `(Promise T)`.”.
The contracts in `typed-racket-lib/typed-racket/static-contracts/combinators/structural.rkt` should be just a single identifier, not a lambda expression, because `typed-racket-lib/typed-racket/private/type-contract.rkt` relies on that, and passes the contract name to free-identifier=?, which won't work on a lambda.
