" So is it true that libreboot leaves the gnu project?"
Yes, Leah says she removed it from the GNU Project. That can be seen in her message although https://www.gnu.org/software/ still says it's a GNU Package but perhaps that just hasn't been updated. Although that question seems unimportant. Libreboot still exists regardless. The whole thing is, in my view, an overreaction to the events that happened especially given that they appear to be false.