It's being rolled out, but it's now opt in and protected by Windows Hello. The saved data is encrypted and doesn't leave your device. Functionally it's an AI version of the existing search and index mechanism which has been around for decades and which also creates searchable on disk metadata from your PCs files. It actually looks quite useful, but I'm also understanding of those who are suspicious of it. If you don't want the Recall feature don't install it.

You also do not have to update to 24H2 at the moment if you don't want to but bear in mind that all these feature updates have their own end of life cycle dates (think of them as new versions of Windows), and will eventually be force fed as older releases go out of support. Typically each major OS update is fully supported for 2 years, and then goes on extended support.

(I suspect you are talking about looking into stopping this feature update, but for others reading this at a later date and maybe confusing an OS feature update with Windows Update, I really would not recommend disabling Windows Update.)