Nice in concept but...
I love the idea of being able to use python instead of their terrible BASIC (VBA), but now /every single/ python calculation in the spreadsheet gets sent to TEH CLAUDE and back?
So now even simple spreadsheets are network chatterboxes and don't work at all if you don't have network access, like on a plane or way the eff out in the field, or maybe your ISP is just having yet another outage.
The obvious reasoning for this is so they can have a peek at your data and even more so they can charge you fat subscription fees for it. They're trying to make Office entirely cloud hosted anyhow (so you can't even run it locally) so this would be one more step towards that.