Was the “raid” successful? By no means, the people who went there from tumblr had no idea what they were doing or how the threads work, only three threads were created that I have discovered. That much, at least, is accurate (typical for SJ/feminist types, there is some connection to reality, however minimal and distorted). The “attack on 4chan” was a dismal display, and members of /b/ were in some cases shocked to learn that they had been “raided.” Here is the general sentiment of /b/ towards the raid nonetheless:
After this exhaustive search that has taken me most of the day, I find no proof that it started outside of tumblr. If one looks at the events of this year: bikini bridge, free bleeding, end father’s day, ect. it does not take any measure of extrapolation to conclude that feminists would attempt to retaliate against 4chan and try to get it shut down. It is not unusually insane by the standards of this website, and if one goes through the notes on shutdown, one finds as much credence from the SJW crowd as incredulity.
Now, Poe’s Law inevitably has a role in all of this. Because this is the internet and we are dealing with 4chan, there is a possibility that it was just a 4chan troll (a particularly exceptional one, that is). Poe’s Law rules supreme here on tumblr. It is next to impossible to discern the satirists from those who are serious, especially when it comes to feminism and feminists here, who oftentimes look like parodies of themselves even while being deadly serious. But, after searching through and reading everything that shutdown4chan has posted across the web (even found a Steam account that I browsed through) I seriously doubt that this was the work of a 4chan troll trying to troll 4chan. Shutdown4chan has a coherent (at least to them) narrative that they do not deviate from, and the people who like and reblogged from shutdown, are all people that one would assume would latch onto a movement like this (genderfluid 15 year olds and all).
In other words: Tumblr started this battle. This was a failed attempt at retaliation after the antics of 4chan throughout the past year. The result is what you have seen in the tags, and, considering 4chan’s history, it was a very minor demonstration at that.