Japanese minor here, I'll start with the balance changes and edit in the splatfest stuff afterward. NOTE: My Japanese is far from perfect, so don't treat this as a perfect translation, as my strength is more in speaking than reading. I put my own thoughts on the possibly unclear bits in italics, as some of it didn't make full sense to me either.
Splatfest Alterations (Bullets are the main points, 'quotes' are the sub-points):
- When an enemy team isn't found and the time is exhausted, the game will attempt to make a game with a team from the same Splatfest team. (They used plain "team" a lot here, so I'm not 100% sure on this)
You can acquire Splatfest points from battles against the same team.
At the end of the Splatfest, only points from games against the opposing team will count towards the end result.
- Made adjustments so that when you start the game before the Splatfest starting time, you may begin to participate at a maximum five minutes before the official start time (Once the official start time passes, you will quickly be able to join with the full event).
This aims to clear the server congestion at the Splatfest start time.
(I'm guessing this refers to starting just before Splatfest begins so you don't get bubbled away from the main group or something, I'm not sure myself)
- Increased the number of Super Sea Snails gained by those on the losing team who received the "Champion" and "King/Queen" ranks.
(Japanese has it as "Charismatic" and "Eternal", I'm guessing these are the two highest ranks)
Special Attacks:
- Inkstrike: Fixed the bug where the painted area differed largely based on the location of the impact. (Altered translation credit to /u/Arbaal)
- Kraken: When in kraken form and you receive an enemy's attack, a stronger repulsion will occur than what is currently present.
(think like the Bubbler's pushback)
Gear Abilities:
- Ninja Squid: Swim speed in ink has been reduced further than what is currently present.
- Stealth Jump: Charging time for the super jump has been lengthened.
- Ink Resistance: Decreased the [ability's] effect on damage taken and movement speed reduction when walking in enemy ink.