We're not sure what Intelligent search means in this context. The ability to search through your notes, whether text-based or handwritten, using specific words was already available on older Samsung Notes versions. On the other hand, the addition of hashtags mentioned by the changelog is self-explanatory, and so are the undo/redo buttons in text mode. Indeed, these were missing on older Notes versions. Undo/redo buttons are a most-welcomed quality of life improvement, and they probably should have been there from the beginning.
These Samsung Notes features were first introduced with the Galaxy S20 series. The flagships could take advantage of them out of the box. The company is now pushing them to all of its devices that are compatible with the app, meaning pretty much every Galaxy smartphone and tablet running Android 7 and up. If you happen to own one, you can grab the latest update by opening the Galaxy Store, tapping the hamburger menu and then accessing the Updates section.
Do keep in mind that some devices will get the update later than others. As of this writing, the new Samsung Notes update is available for the Galaxy Note 10 but missing on the Note 10 Lite, though that should change in the near future.
