1::1s are confidential, no exceptions.
If you are the superior holding a 1::1, then send a copy of your notes to the other person afterwards–preferably using email as it's more durable than Slack. You may store a copy in your private archive, but under no circumstance should 1::1 notes be uploaded to Confluence, the company Google Drive or any other company owned tool. This is because admins could theoretically overwrite your permission settings, and violate the sanctity of the 1::1.
Superiors are responsible for setting up 1::1s with their reports.
The superior should spend most of the time listening, this is your chance to get a pulse on how things are going.
The superior should never cancel a 1::1.
Reports should also not cancel a 1::1. If you have nothing to talk about, then say hi and end early.
If a 1::1 cannot take place, then reschedule it. Don't postpone it until the next cycle.
Anyone can request a 1::1 with the CEO, even if you are not in the Management team. In principle you can ask for 1::1s with anyone, feel free to pick your mentors, even if they're in other teams. Just ask.