We've noticed how the church has rolled back using the term Lamanite to identify groups of people with Native American ancestry (North, Central and South America), especially in light of the lack of DNA and archaeology supporting the Book of Mormon and the futility of narrowing down the location of the Book of Mormon.

What have the mission presidents and missionaries been taught and, in return, been telling people in their missions? For example, are missionaries telling Brazillians, Mexicans, etc they are Lamanites or descendants of the people described in the Book of Mormon. I know they used to do this in the past but is this type of thing discontinued? What were you RM's saying and being taught in your missions if you served in the last 15 years?

This doesn't directly answer your question, but as late as 2013, Dieter Fuchtdorf was telling Hondurans that they were descended from Lehi.

http://exmormon.org/phorum/read.php?2,844298

My Honduran mission president, Salomon Jaar, certainly thought that Hondurans were descended from Lamanites. He also predicted that his mission president, Carlos Amado, would be the first "Lamanite apostle."

http://www.deseretnews.com/article/700025080/Former-LDS-mission-president-Honduran-official-killed-by-robbers.html

I believe that position was claimed by George Lee who was later excommunicated.

https://en.wikipedia.org/wiki/George_P._Lee

Presidente Jaar! I spent a year under that man and he absolutely believed they were Lamanites. When were you in Tegucigalpa?

One interesting distinction lately is:
The "lamanite generation" has turned into the "living legends" But the church still celebrates half nude Polynesians at their amusement park in Hawaii.