Twitter is already a disaster if you don't pay attention to the accounts you follow. I don't see this changing much of anything in my twitter feed. If it does then I will cull the list of things I follow even further.
In a broader context, has banning dipshits, scumbags and racists from twitter lessened the number of dipshits, scumbags and racists? No. Has it reduced the impact of those dipshits, scumbags and racists? No.