Here is item filter information straight from GGG's official announcements. They also include information such as new item filter enhancements and functionalities, most notably in the 3.4 Delve league announcement. As far as map information I would only look at the newest patch. I will list some notable (or valuable) new items per patch, the div cards listed are worth upwards of 20 Chaos with some worth multiple exalts. Prices checked on poe.ninja and can fluctuate.
3.1 Abyss league
Notable additions: Stygian Vise belt, considered best in slot for most builds due to the abyssal socket (which holds the equally important abyss jewels) implicit being straight up better than any other implicit. New currency item Orb of Annulment, a little above the value of a divine (currently)
Bestiary orbs and nets can be ignored as this content wasn't added to the base game.
Notable: Div cards the Iron bard and World Eater
Filter additions: HasExplicitMod, StackSize, GemLevel
Notable: Incursion items Stone of Passage and Flashpowder kegs. Multiple Vials used for upgrading Incursion league uniques. Div cards Immortal Resolve, The Celestial Stone, The Samurai's Eye, and The Mayor
Filter Additions: Custom sounds, light beam effects, minimap icons
Notable: Delve items including fossils and resonators. Div card Beauty Through Death
Notable: Scarab map fragments, Div cards A Dab of Ink and The Nurse.