I don't think so, mostly because the first shots of the Second Great War were fired in Europe by France declaring war on Germany, not Featherston initiating Operation Blackbeard.
I don't even think the Population Reduction would be enough for Featherston to be loathed worldwide and I'll explain why.
Let's compare what Featherston did to blacks in the Confederacy to Germany's genocide of the Herero and Nama peoples. The latter, while it certainly happened, is not widely discussed, because it happened outside of the European field of view, as it were. It didn't happen in Europe, it happened in some colony that no one cared about in the early 20th Century. This is surprising, given how some of the racial theories that led to the Holocaust were born in Africa.
Similarly, the Population Reduction didn't happen in Europe, it happened in a place which could be considered a British client state, out of sight and out of mind for most people in the world.
Also, the Population Reduction lacks the geographical reach of the Holocaust. The Holocaust annihlated entire Jewish communities across Europe, the Jewish community in Poland and Thessalonika, Greece, comes to mind, while the Reduction was mostly limited to blacks in the Confederacy, except for at least one death camp in Haiti, a country that I doubt most 20th Century Europeans would've thought twice about. This would've been like the Armenian Genocide. Yes, it happened, but it mostly happened in a particular country and against a minority group that no one in Europe really cared about. There's a reason why no one knows who the three Pashas are, outside of people on this site, because nobody talks about the Armenian Genocide.
Also, the Holocaust happened in a time where we were slowly realizing that perhaps racial prejudice should be a thing of the past. In this timeline, Germany won the Great War and as a result, still holds Namibia, where in OTL, the first genocide of the 20th Century happened. Do you really think the Germans will bring much attention to the Reduction with that big blotch on their colonial record?
And of course, the American Front of the Second Great War, to the other European powers, was a insignifcant front, the fourth chapter in a epoch of mutual national hatred which while it would concern the USA, does not concern the other foreign powers. Again, the main front of the Second Great War is Europe. If anything, in Europe, they'll focus on Russia's atrocities towards the Jews of Eastern Europe, not whatever is going on in North America.
A simplistic caricature of Jake Featherston is guaranteed.
(Seriously, in War and Remembrance, Hitler is screaming his head off half the time)