9.3.0 / 2026-03-10

• feat(schema): support discriminators option inline for better TypeScript support #16053
• feat(aggregate): add pipelineForUnionWith() helper to allow reusing pipelines with $unionWith in TypeScript #16033
• feat(setDefaultsOnInsert): pass query as context to default functions #16041 #16025
• fix: resolve deeply nested discriminator paths in arrayFilters #16072 Yatin81
• fix(changeStream): emit ready on next tick to allow stream to initialize
• fix(connection): handle calling watch() on disconnected connection
• fix: remove references to mongodb option "promiseLibrary" hasezoey
• fix(model+query): backwards compatible validateBeforeSave handling and avoid TypeError in removeUnusedArrayFilters on nullish update
• perf(model): remove unnecessary overhead when saving new doc
• types(InferRawDocType): fall back to using InferRawDocType instead of pulling non-raw inferred doc type if EnforcedDocType not set #16053
• types: add type constraints for Document#$model() and Document#model() mrazauskas
• docs: fix broken links and update MongoDB documentation links #16037 hasezoey
• docs(contributing): update issue tracker links to Automattic org AkaHarshit