There was no #Anonymous blackout on March 31. For example, here is a graph for traffic to one of those servers. As you can see, there is no unusual traffic today (Saturday, the far right of the graph). This Saturday's traffic looks little different than last Saturday's (to the left).
As to whether the threat was "real" is a philosophical question. Many famous #Anonymous identities (e.g. @YourAnonNews) disavowed it. But there is no single official "Anonymous", so nobody truly has the authority to disavow it. If enough people undertake the attack in the name of "Anonymous", then it's a "real" attack, regardless if some others disagree.
With that said, there was no easy download of the "ramp" tool. There was no link to it in the original PasteBin post that announced the attack. The whole point of DDoS is to distribute your tool to as many many people as possible so they can all attack the target. No tool distribution means no attack. Whether the person who authored the original PasteBin link intended to follow up with a posting of the "ramp" tool is an unanswered question. The number of people that would've downloaded and run the tool is likewise an unanswered question.
I tend to agree that it probably wouldn't have been popular in the #Anonymous community. And, as I pointed out earlier, it probably wouldn't have worked even with the full weight of #Anonymous behind it.