Hweis Ability reveal dropped and inside you can find a number of preseason changes, including map changes and Changes to Items, credit to Skinspotlights for the video, Link

Map changes:

The map is no longer (close to) symmetrical, anything listed is specifically for the locations detailed, though it does seem there was an effort made that ganking lanes is now more properly balanced out between blue and red side (Right now ganking Top is easier for Blue side Junglers and bot for Redside Junglers due to the entrance near their T1 towers)

Baron pit is the same until Baron spawns where it looks like Baron Broke down part of the pits walls as a linear Path is now carved through the pit.

Area around Mid T1 is way more open and the Jungle entrances on the south west/north east now force you to move through the Tower, walls adjusted to fit this. The long Brushes connecting Mid to the River seem to be moved outward towards River. The tower itself also looks to be moved back a little. Actually every T1 tower looks to be moved further back in lane.

The Brush on the upper part of bot side River on the red side entrance to Blue buff Quadrant is gone or moved, hard to make out in the video.

The jungle entrance between mid T1 and T2 coming from the Red buff Quadrant is different, more open than before and compared to the same entrance on Red Side

Maybe Im tripping but mid as a whole looks alot more open

Red side top entrance at T1 turret moved back, is now behind the turret instead of in front of it, killing this gank path

Blue Side bot lane now has 4 Jungle entrances with the current middle one split.

Red side botlane new Jungle entrance near Gromp

New Path added between river and Blue buff (both sides)

Red side Jungle entrance near botside T1 moved, you might be able to enter bot lane now from there without being in Towers shooting range (you should be in Vision though)

The thin wall between bot side Blue buff side Jungle and River is gone

Theres now a pixel brush on bot side river, the Brush along side the eastern River wall is gone, so is Pixel Brush on the upper part of Bot side river, top side River is uncertain but the Pixelbrush there isnt there anymore where it used to be.

Items:

Haunting guise is back, Liandries no longer a mana Item, Ludens and Liandries buyable alongside each other.

Triforce now builds out of Noonquiver

Ancient coin (Yellow supp Item) is back

Yuumi has what seems like new potions and no supp Item, she later also has the skillpoint pot in her inventory, possible Klepto return? (She has spellbook as Keystone though)

Nocturne has a weird looking Item in his inventory at one point and it seems to build into Axiom Arc, Icon seems Placeholder like.

Kaisa has a new Item at one point

Pets are still there

Red side team has a 3 stack buff using the ZZrot Icon for some reason (no the Item isnt back)

Several champions have a Yellow Shield Icon next to their Healthbars that I dont know where its from.

Ludens cd is noticeably lower and has some sort of stacking mechanic.

Completed Items that seem to stay around: Ludens, Liandries, Mejais, Shadowflame, Cleaver, Ghostblade, Eclipse, Axiom Arc, Nashors, Stormrazor, Navori, Imperial Mandate, Shurelyas, Triforce, Ravenous, Chempunk chainsword, Rocketbelt, Voidstaff (Now builds from Needlessly?), Rageblade, Kraken, Staff of flowing water, Moonstone.

If anyone finds some more things lmk

Note that nothing here is confirmed and subject to change, who knows when this was recorded