I can break down the 4.0 update from a German Youtube video. All credits of this information came from German Youtuber Unleash the Pixel.

Here are the goods, the bad and the ugly of 4.0:

The goods: Survival Trials, New Map Areas, Kakashi Handbook and Group Summons

-Survival Trials have difficult modes ranging from C, B, A, S and SS. Higher difficulty yields better rewards if you're at the top of your server.

-New Map Areas. Turtle island and 2 other areas will be added to world map for new weekly events in the future.

-Kakashi Handbook gets a prettier interface make over and generates better daily rewards.

-New group summons, a promise from 3.0 will finally be added after 4.0

The Bad: Convoy/Plunder nerfs/buffs and balance. You can run both convoys and plunders on the same day. SS convoy yields 30 coupons (-5 nerf from current update). If your SS convoy get plunder, you only lose 5 coupons (you get back 25, buff from current update). Here is the big nerf, after first free SS convoy and plunder, it costs 15 ingots (10 for additional SS convoys? German speakers please verify) for additional plunders in the same day. Here is the balance, a successful convoy or plunder can grant you random chances of receiving a command seal that replaces the ingots consumption. Refresh timer for convoys missions changed from 30 minutes down to 20 minutes.

The ugly: Cross Server GNW. All F2p and low paying p2p (pay to play) get their seal scrolls from weekly GNW. Remember how hard it was to get advanced refine runes after Sage Worlds became cross? Now imagine how hard it would take to get seal scrolls after GNW becomes cross. I hope Oasis balance this problem by increasing the seal scroll prizes for GNW participants like they do for Sage Worlds.

Minor stuff: There are other small details I deliberately leave out from this post as I don't care too much about it such as group menu interface small makeover and other UI changes to fit computers with small screens.

All of this information are extracted from the video I found on Youtube by Unleash the Pixel. I am not a German speaker, anyone from Germany are free to share or alter any information I missed.

PS: Mods please don't delete this post. Most players are already bored of this game. Educating players on whats to come in 2 months will keep them motivated to continue playing and spending.