[Spring] [Reactive] Controller parameters wrapped in Mono

A generated controller method for Webflux (spring, reactive) look like this:

public Mono<ResponseEntity<MyModel>> createModel(
    @Valid @RequestBody Mono<MyCreateModel> myCreateModel,
        ServerWebExchange exchange) throws Exception { ...

Q1: Why is myCreateModel parameter wrapped with a Mono?

Q2: Do I need ServerWebExchange param? If not, can I disable the generation?

Thx