Early in this link, they bring up the title page of the BoM that was recently changed by the church. This quotes Smith saying in the Times and Seasons saying the title page wasnt invented by him, but rather it was written on the plates he translated.

So the wording in the preface was on the fictional gold plates and should not have been changed to say the Lamanites were "among". The plates themselves had the original wording.

http://www.mrm.org/dna

Yes, but don't forget, the Mormon god can change his mind whenever he wants. And he does so often, especially after his original words are proven to be incorrect or false.

Almost all of the early Book of Commandments/D&C "thus saith the lord" revelations were extensively rewritten to reflect mayor changes in Joseph Smith's, er, god's developing theology. This is especially true of those concerned with visions, priesthood offices, and the Missouri "United Firm" as the Mormon god first called it.

That was not in the title page. It was in the introduction written by the church years later.

The title page and the introduction are two distinct items.

The introduction ("…the principal -> among the ancestors of the American Indians") was written for the 1981 edition of the BOM. It's not in pre-1981 editions, and was never claimed as part of the plates.

The title page ("Wherefore, it is an abridgment…") is the part alleged by JS to have been on the plates.