So, in order to be succint: starting from Season 3, 2v2 will no longer be a solo Ranked queue, which means teams will still be able to play Ranked 2v2, but if you are playing alone your only option will be 3v3.
They gave three main reasons for this change –first, as 3v3 and 2v2 share leaderboards, it gave birth to an unintended tendency in some players to play 2v2 in order to rank up faster, something even noticable in high population regions, which would made them unable to play 3v3 even when they wanted to just to keep their high rank. Second, seeing as 3v3 is the main focus of any balance in the game, they want to incite players to see it as the primary competitive mode of Battlerite. And third, with Battlerite Royale just around the corner, and being a mode mainly for solo and duo experience, they believe the arena will benefit from a 3v3 focus.
They did also talk in a previous blog about how 3v3 and 2v2 have a place in Ranked, in which they also stated that 2v2 is the most popular mode precisely because you can just join in with a friend, hence the ranked mode change won't really have that much "impact".
There are three major upcoming changes with the arrival of Season 3:
With Season 3, arena matches will last only 1:30 minutes instead of the 2:00, as most rounds don't really the end of the timer before they end. This way, it will be more likely for the Vortex to appear and close in with everyone still alive, yet in most arena matches it still wouldn't happen.
As a side note, they will also add this new timeframe to the options when creating a private match.
Support M2 Cooldowns
Right now, the ability located in this button for Ulric, Blossom, Lucie, Oldur, Pearl and Sirius works in such a way that depending on how many allies you have around, its cooldown gets reduced. However, this will change so that your cooldown will depend on how many players are still alive. The reason they gave to this change was that they wanted teams with disadvantage to be able to heal at the same pace as the leading one, even if in general matches in this kind of setting will end quicker all the same. Of course, champions with M1 based heals are exceptions to this change.
Numbers as to how this cooldown will work will be released on a later date.
This debuff will receive a minor rework: currently, weaken reduces the damage from a champion by 50%, and can stack twice, further reducing the damage a 100%. However, once Season 3 starts weaken will no longer reach such a number, capping at 75%.
Seeing as a 100% damage reduction was becoming more and more unhealthy, I personally welcome the tweak. It's still strong, it can save an ally if well used, but you won't find yourself risking an engage and getting 0 from it.
In general, I believe these are some healthy changes which the game needed, yet I also understand the reticency the developers had, as there will be some players who will leave the game just because of the 2v2 changes… still, the game is balanced for 3v3, its competitive mode, and those players will also receive the Battlerite Royale which may become quite the experience for them.
And that's all! I tried to be as concise as possible. Read it directly from the blog.