'{}' feature or bug?

[Mikael Adolfsson <d87-man@ludd.luth.se>]

This struck me as an inconsistent behaviour, but perhaps it's
intentional.  If it is, I can't see why.  I don't like it.

     ; }
     syntax error
     ; '}'
     }: No such file or directory
     ; '{'
     {: No such file or directory

the above is ok, but what about the rest?

     ; '{}'
     ; '{echo strange}'
     strange
     ;