For some, "Christian" (adj.) no longer includes Lutherans

[Joanne M. Despres]

But as long as the shift in meaning has only occurred "for some,"  I
don't think we have to worry much that mainstream dictionaries
would change their definitions of "Christian" or, for that matter, that
non-fundamentalist Christians would stop using using the term of
themselves just because somebody else is trying to appropriate it.
There are always going to be crackpots announcing that a widely-
accepted definition is wrong because they don't happen to like it;
but that doesn't mean their campaigns to change the language (or
dictionary entries) will be successful.  In fact, it seems to me that
they almost never are, because the "new" definitions are used by
too narrow a group of speakers to justify their entry.

For whatever it's worth...

Joanne