I can't fill you in on the Eastern scene because I don't follow it, but I can do the west, sort of. Team Secret and Team Tinker are both collections of TI4 players who left their teams. Na'Vi, Alliance, C9, EG, Fnatic, and PR are still around, but with some major roster changes. Notably, Na'Vi replaced its only non-Ukrainian players with ex-Power Rangers players, which has given them a level of YOLO that is beyond the understanding of mere humans like you or I.
Here's a fun team secret game to watch:
https://www.youtube.com/watch?v=n5Sek5- ... aFNJ0Dmg8wThe patch: I've played 5-10 games since the patch, and here are my impressions:
1: The gold from death changes are the biggest change. When you kill a hero who has a really high net worth on a team whose net worth is significantly higher than yours, you get a TON of gold. This means that heroes based on getting a gold advantage through early ganking (Bounty Hunter, Nyx Assassin, Huskar) and carries whose power comes more from being able to outfarm their opponent than being able to use that farm exceptionally well (Antimage, Alchemist, Doom) get a lot worse, while heroes who don't farm very well, but make good use of gold (spectre, medusa) get stronger. Gameplay wise, it means that if you're ahead, you need to be very, VERY careful not go get picked off, even if it means getting multiple kills on enemy heroes, but if you're behind, you want to take fights as often as you can.
2: The rune change was the 2nd biggest change. Since you're guaranteed a rune, heroes are encouraged to leave their lanes to contest the rune spots. This means multiple heroes meeting up in the middle of the river, far away from any towers. This means fights. I really like how this breaks down the passive laning stage.
3: The changes to towers are the 3rd biggest. Towers now give less gold, and tier 1s reset glyph cooldown when they die. This goes hand in hand with #1 in killing snowball heroes and teams, and pushing towards more lategame oriented lineups.
4: The map restructuring are the 4th biggest. First of all, offlane is now super easy to gank. You can wrap around through the new paths in the trees, and use those same paths to escape after you get the kill. Second, the secret shop/ancients area is a lot less safe. After they take down your tier 1, they can go into it through the new paths without being spotted by your T2. Third, rosh is more dangerous. The pit leads directly out into the river, making escape difficult.