… just your privacy, but I guess that’s not important to the majority of bleating sheep. Incidentally, Office 365 local apps can be set to save locally.
The real question is whether the Macbook Air can boot. If it can’t, then you’ll need an adapter for the disk drive. The actual interface varies from proprietary PATA, to SATA (I think), to PCIe on the latest models. All of which have USB adapters, but you need the right kind.