new buffer - should its mode reflect its name when the name matches auto-mode-alist?

[Drew Adams]

Haven't thought about this before, but I wonder if the mode should respect
auto-mode-alist when you create a new buffer? There's no doubt a good reason or
two why we don't do this - just wondering.
 
E.g. `C-x b foo.el', where there is no existing buffer foo.el. The mode is
Fundamental; should it be Emacs-Lisp instead?

(I realize that a new buffer need not be intended to be saved as a file.)