I think you may be confusing Microsoft Copilot with Microsoft365 Copilot? The first doesn’t give you access to Microsoft Copilot Studio but that might also be available with Microsoft Copilot Pro.
Someone within Microsoft really needs to forward this entire thread over to their marketing department.
I believe you might be confusing Copilot Search with Copilot+? Which is of course different from Copilot Pro though not necessarily entirely distinct.
And Sam Altman thought that they were bad at naming things. Good thing they were bought up by the king of naming things. /s
Edit: They are doubling down on bad naming conventions so hard that it makes me think it's some kind of dark pattern sales strategy..
My confusion has only increased.