“Two-spirit” refers to a person who identifies as having both a masculine and a feminine spirit, and is used by some Indigenous people to describe their sexual, gender and/or spiritual identity. As an umbrella term it may encompass same-sex attraction and a wide variety of gender variance, including people who might be described in Western culture as gay, lesbian, bisexual, transsexual, transgender, gender queer, cross-dressers or who have multiple gender identities. Two-spirit can also include relationships that could be considered poly. The creation of the term “two-spirit” is attributed to Albert McLeod, who proposed its use during the Third Annual Inter-tribal Native American, First Nations, Gay and Lesbian American Conference, held in Winnipeg in 1990. The term is a translation of the Anishinaabemowin term niizh manidoowag, two spirits. Two-spirit people may also reclaim traditions related to same-sex attraction or gender variance within Indigenous communities. These can include terms such as the Lakota’s winkt or the Dinéh’s nàdleehé, both of which refer to men who fill social roles associated with women, or terms which refer only to sexuality, such as the Mi’kmaq phrase Geenumu Gessalagee, which means “he loves men.” Because the term two-spirit was developed by Indigenous people to describe experiences of their communities, the use of this term by people who are not Indigenous is considered cultural appropriation. For some, two-spiritedness is more than just an identity; it is a traditional role that some Indigenous people now embody in their modern lives.

It's not the same thing, and they didn't just tack on another acronym, it's been apart of the LGBTQ+ acronym for decades. Whether the acronym is getting excessive or not is irrelevant (I think it is, which is why I shorten to LGBTQ+), it's still a separate identity.