I think it would really awesome if Chameleon made an appearance in One Piece Burning Blood 2(if there's a sequel). Especially with his unique devil fruit ability by copying other people's powers. The type of playable character I think he would be is either tricky or technical because to me he seems like assassin type character.
As for the feedback results, it might take about 2 month because Japan feedback started in April 21 and ended on July 20. The major patch was on June 23 which probably base off Japan feedbacks, but every single one. Same for the upcoming patch for August. So, the next patch update will be a worldwide feedback.
However, you're still able to send more feedback on Bandai Namco Japan website which is what most of users in the 2ch website on One Piece Burning Blood thread are doing.
And it looks like we will get the first gold DLC pack this week. I can't wait to play as playboy aka Gildo Tesoro. Remember, if you have the Japanese version, you get the first DLC pack for free, but limited for 2 weeks.