It will later be included in Windows 11, version 23H2, the annual feature update for Window 11, which will be released in Q4 of this calendar year. With the feature update, Copilot in Windows will be on by default, but under your control with Microsoft Intune policy or Group Policy.

techcommunity.microsoft.com/t5/…/3933653

Copilot will begin to roll out in its early form as part of our free update to Windows 11, starting Sept. 26 — and across Bing, Edge, and Microsoft 365 Copilot this fall.

…microsoft.com/…/announcing-microsoft-copilot-you…

I am fairly certain that “Copilot for windows” will be “free” while the more advanced Microsoft 365 Copilot will be the one that costs $30 extra per user (on top of any licenses like E3 or E5)