2018 Sun Dec 9

VSCode defaults to using its own built in TypeSript. Does not use the one a project has installed (aka. workspace). Can be configured to.
Omit can be derived from Exclude but is not part of the TypeScript utility types stdlib. Exclude works on sets like a | b | c while Omit removes fields from an object. This and many other utility implementations can be found at https://github.com/piotrwitek/utility-type.