The first one is a pretty nitpicking one, IMO; all that's happened is that then/fmap and map have been collapsed into a single function that dynamically dispatches on the type of the returned value to decide which behavior to execute. More of an ergonomic convenience for programmers who don't quite grasp the distinction.

Edit: And with regard to the side effect ordering question -monads are only well-known defined for pure functions anyway! By that standard, any Scala code using non-pure functions is also not using a monad. This I inevitable in a language that does not enforce purity, which is basically every widely-adopted one that's not Haskell. A definition of "support" that excludes implementations that allow (but do not require) non-pure functions is not a very useful definition.