I originally thought it was an excessive amount of letters to describe those of us under the rainbow but no, it makes more sense in the context of the article I do not really agree with combining the two but to each their own I guess.
MMIWG2SLGBTQQIA+ stands for missing and murdered Indigenous women, girls, two-spirit, lesbian, gay, bisexual, transgender, queer, questioning, intersex and asexual+. It’s derived in part from the more commonly used initialisms MMIWG (missing and murdered Indigenous women and girls) and 2SLGBTQ+.
There already is a word that encompasses it, “Queer”.
The only people that generally want to keep adding more letters to the acronym are so-called “Allies” and not members of those groups themselves. Most members of those groups (in my experience) are more than happy to call themselves Queer and then give you a funny look when you start talking gibberish.