This is a good addition; however, this new feature simply creates a summary to use in the invite. We have not been able to reproduce the successful outcome of what davedres shows in the comment above.
M365 Copilot (at least in our tenant) still does not have the ability to accurately understand and interpret calendar availability. Try asking Copilot (Work / Bizchat) to find the next available slot when you and a few others within your org are available. It cannot - you will receive recommended slots from Copilot during times when other meetings are booked.
Copilot inaccurately indicates that I have availability during times when I do not. Ideally, Copilot could check my calendar, find the open slots, and draft a response with my availability. This would save me time from manually checking each slot before responding.
I have a support ticket open for this issue from early November, and the MS support engineer has been able to reproduce the same. I'm hoping to see this gap addressed by PG soon!