Message Mode and bidi

[Christopher Culver]

Modes like text-mode and Org mode now have good support for
bidirectional text. When one switches to an input method for a
right-to-left language, like farsi-translit-banan, and types a letter,
the text is immediately aligned to the right side of the window and the
cursor appears correctly to the left of the typed text.

This functionality is missing from Message Mode, as I find when writing
a new e-mail in Gnus. Right-to-left text can be inserted there, but the
text is not aligned to the right side of the window, and the cursor
incorrectly appears to the right of the typed text.

Thus my question is: is this a bug in Message Mode that could be
reported, i.e. the required functionality has not been implemented there
as in other popular modes?  Or does this lack of full bidi support in
this mode represent a deliberate choice on the part of Emacs devs?