Of course it's for the better. Less saturation... Top Rank and GBP have always been rivals, and big fights have always been harder to sign, especially when the fighters are promoted by rival companies.. I 've heard ESB'ers say all the time how they admire the UFC's model, where the best fighters usually fight the other best fighters. There's no politics to get in the way. The UFC is one unified organization. With Bob Arum and Top Rank out of the way, Golden Boy can take over and more big fights will be made without many obstacles in the way.
I think GB will take over. I do not think Arum is really that great for boxing. His PPVs were always one main great fight, and then terrible mismatches on the undercards. Don King usually had a great full card. In someways the PPVs with GB have been a lot like Bob Arums. They seem to do the good main event and terrible mismatches on the undercards. If boxing is there, there will always be a promoter to make money.
What happens? NOTHING Bob Arum not being around doesnt mean TOP RANK isnt still there making the same fights same fighters e.t.c