Did not see any thread about that so sorry if this was already post
Still a rumor but would definitely be interesting to see especially the fact that they apparently plan a free to play version.
According to the rumor, Sony would be developing the title so as to publish it for the launch in 2020 for PlayStation 5. They will put in lots of money to finance this project because they think it will boost PlayStation 5's appeal on launch. It will then be launched in 2021 on PC. This would be in line with Shawn Layden's statements regarding how he wants Sony to publish their games on other platforms. However, there won't be cross play.
If it follows the Super Smash Bros. formula, it will have over the top animations. They will also presumably have cartoon-like graphics and the gameplay will be made so that it can attract both casual and eSport players.
Still a rumor but would definitely be interesting to see especially the fact that they apparently plan a free to play version.