D decide to leave their management company, because if they think they will do international tour and so on, they think that it is hard to produce over 20 songs every year at the moment. This is not because avex or smile company want to kick them out. actually they tried to keep them, but they decided to leave.
They are going to work with old staffs (They are not saying the staffs are from avex or smile but they are saying that the staffs are people who they have been working since they were indies)
Basically they are saying thank you to all avex and smile company people who they had been working with. and they are saying that even if they go back the indies label again, their quality will not change so please look forward to it.