Should update Schema Salad specification v1.2 to indicate the old behavior (can only subtype simple classes) and describe the new behavior in Schema Salad spec v1.3
SpecializeTo should be is_subtype of SpecializeFrom if it isn't checked already, maybe another thing to add for Schema Salad v1.3 spec
_Originally posted by @tetron in https://github.com/common-workflow-language/schema_salad/pull/741#pullrequestreview-1642504338_