C# comes from a statically typed language tradition (the dynamic keyword aside) and has very little in common with Javascript beyond the surface level of curly braces. The trend in C# features seems very much influenced by functional programming, adapted to be more familiar and palatable to non functional programmers.
Some features of C# that seem influenced by functional programming in general or F# in particular include lambdas, type inference, Enumerable (F# pipelines), pattern matching, tuples, null coalescing (a Maybe if you squint), expression bodied members, record types and Range expressions. There is also what looks like an 'aesthetic' influence of F# in language features that reduce ceremony and make for more concise code like auto properties as well as a functional inspired recommended practice of making immutable types.
My comment regards JavaScript was more about to pick up
existing developers. C# was always meant for productivity. A rapid learning curve (as opposed to learning functional programming first) is very important here.
Some features of C# that seem influenced by functional programming in general or F# in particular include lambdas, type inference, Enumerable (F# pipelines), pattern matching, tuples, null coalescing (a Maybe if you squint), expression bodied members, record types and Range expressions. There is also what looks like an 'aesthetic' influence of F# in language features that reduce ceremony and make for more concise code like auto properties as well as a functional inspired recommended practice of making immutable types.