I am not a fan of introducing curly brackets in a similar way I am not a fan of curly-bracketisms in F#, it makes for a clumsy noise to a relative distraction-free language like OCaml. It feels like trying to get Algol-family programmers on board, whereas OCaml users have been using ( and ) as well as begin/end since a long time.
But an advantage I see with the new comment syntax is that there are is that there is no ambiguity what the hell (*) is. At least this.
Expressions of various kinds - Async, seq, query, etc; record type "constructors"... that's all I can think of off the top of my head.
F# in general is a beautiful language though, I can't say I've ever thought about the "curly bracketisms" personally because I'm too busy being excited about how much fun it is to write over C#.
But an advantage I see with the new comment syntax is that there are is that there is no ambiguity what the hell (*) is. At least this.