This Atlantic piece is a good overview of the legal overview of McGirt:
At least with respect to Indian law, several tribal attorneys told me, this Supreme Court might just be the Gorsuch Court. Tribal attorneys “will be quoting that decision for the rest of our lives,” Riyaz Kanji, the lawyer who argued the McGirt case on the tribe’s behalf, told me. “The Court is not going to be in the business of taking away tribal rights without congressional intent anymore.” He added, “I’ve cried a lot today.”
SCOTUSblog put up a good basic summary of the ruling (I wouldn’t call it an analysis as they do), noting it is “…a stunning reaffirmance of the nation’s obligations to Native Americans.” SCOTUSblog, however, is pretty weak on providing coverage of the case as a whole, however. In comparsion to McGirt’s one post, the Trump tax cases got an “analysis post” followed by a six part symposium on the two cases. They’re not alone in this, McGirt – one of the most significant Indian law cases since Worcester v. Georgia – has largely been sidelined. It’s reasonable many news outlets would short change McGirt in light of the tax rulings, after all any news outlet can put out the Trump cases can impact their readers or viewers, whereas McGirt seems to only affect a much smaller subset of the country. Yet the historical and future implications of McGirt’s holding are as fundamentally important, in not more so, than the tax cases. Hopefully SCOTUSblog is planning a similar symposium on McGirt because the case needs more thoughtful analysis than its currently getting.