I think if that was teaked slightly and allowed to settle it would have been an improvement.
The sad individuals that troll any social network do so partly for the reaction. Getting blocked is a "badge of honour" for these pathetic people.
The new system, If I understand it correctly, would have stopped the blockee from seeing the blocked persons tweets to them. This means the troll is unaware they've been blocked and is free to send their virtiol into a black hole never to be seen.
The current system means the troll knows he/she has been blocked hence the purposeful trolling that happens where getting blocked is seen as "winning" a debate or an admission of defeat.
The only downside would have been, to some people, that the blocked person can still read their tweets, but as has been pointed outthats no different to signing up a new, random account and using that to view output from any user who has blocked you. Anyone willing to expend that much effort on it will always find a way to view the tweets they want to see, so they new system would have left them with the impression they were simply being ignored, which doesn't sit well with them. They want attention,