I’m not sure it’s unreadable to an experienced coder, someone learning the language though will be confused about the difference between = and => in the function argument definition.
Also the “arrow” is clearly pointing the wrong way, it should be “<=“.
It adds up. It's right that we have gotten used to all of the other stuff, but it adds up. It's fair to be very critical of new additions.
It's fair to be critical, but calling this flat out awful and unreadable is way overselling it. Whether it helps add up to something less readable than preferable is arguable, but taken on its own this change is minimally invasive and frankly pretty readable.
It seems perfectly readable to me, honestly. It might be confusing to newcomers, but I don't see a problem with it.