The new Apex Legends event, titled "Wild Iron," introduces not only new cosmetic items but also numerous balance changes, quality of life improvements, a new map, and significant updates to game modes. We will try to cover only the most important changes as briefly as possible.
Event Items are not the most interesting feature in this update so that we will reuse the screenshot of the event menu in the game, posted by EA News below, just for general understanding.
The jump master in the ranked has been removed, and now everyone jumps by themselves. If you're not aware, ranked jump differs from public. In ranked jump, players are distributed across the map, and each squad has its designated jump spot, similar to the pro league (ALGS). This setup has led to many players complaining about having to disconnect from every single match, which can be pretty annoying.
Unfortunately, we won't have full-size duos mode in Apex Legends anymore. The developers have decided to make it smaller, reducing the number of squads from 30 to 15 and the number of ring closes to 4, which leads to a smaller map size.
As far as I understand, the reason for that is the popularity of Wildcard mode, which has attracted many players, causing longer matchmaking for non-ranked battle royal modes.
It is arguably the worst character in Apex Legends, not due to his abilities/passives, but rather how he is written, his story, and his design. However, he will be slightly buffed with this update.
We will have some slight buffs, I would even say quality of life improvements.
I think these are the most critical changes in the update, but for more details, you can check the patch note from the original EA News article here.