Seriously, do people not remember that this statement was first made for the first game, in 2007, at a time when so much of what was in the game could've been a political lightning rod? You're playing someone from an organization that was historically associated with Islam, going around killing Crusaders (and everyone else, but still) in the Middle East during the Middle Ages. This was the time of the 2nd Bush administration, the occupation of Iraq was still in full swing, and the news was still filled with daily fearmongering about Muslims and imminent terrorist attacks. IIRC this was still the era of the color coded terror threat levels that the DHS would issue, and that was still getting cited every day on TV nows as if it were the weather or sports scores.

Basically it was a batshit crazy collection of historical, religious, and political trivia that was used as the background for the game's narrative, but at that time there was so much potentially controversial stuff if anyone took it too seriously that it could become a marketing nightmare. Boycotts from Christian groups and/or right wing nutjobs claiming that the game would encourage children (gotta think of the children!) to become Islamic terrorists. That sort of thing. It was a complicated game to market in that atmosphere. All sorts of different groups could have latched on to it as the epitome of how video games rot kids minds and turn them violent. It doesn't require anyone to actually do anything violent, it's just fuel for a gazillion fearmongering rants for Rush Limbaugh, Bill O'Reilly, etc. All they would have to do is describe the game and demonize Ubisoft for making it; instant ratings gold.

They've continued having that statement at the beginning of each game, at this point as more of a tradition I think. Once the franchise was established, and got out of the Crusades, it gradually lost its potential to be a lightning rod for politically- or religiously-motivated anti-video game criticism. Although let's not forget the later game in which you have a boss fight vs. a historical pope who ended up being the villain in that game. Considering how freaked out certain demographics got by things like The Passion of the Christ (the movie), it's not much of a stretch to imagine somebody like Glen Beck going on an anti-video game crusade (no pun intended), throwing gasoline on the fire by going on and on every night about how these evil Canadians made this evil video game where you play an assassin from an order that was historically Islamic, where you're literally sneaking in to the Vatican to kill a historical pope (albeit with non-historical superpowers). Therefore kids are being brainwashed by Ubisoft to become Islamic terrorists right before our eyes. You know, Glen Beck stuff.

So it's really always just been a marketing CYA thing to reassure everyone that the game wasn't made with any particular political/religious/historical agenda. Admittedly, "we've got Catholics therefore we're obviously not in favor of assassinating popes" and the like is the "but I've got black friends" excuse for racism, but FWIW the intention was to proactively disarm accusations of biases or hidden agendas. It was not to be some sort of diversity statement.

But of course, it goes without saying that even if it was a statement of pride in diversity (which it wasn't), WHO THE EFF CARES. People getting triggered by such things need to go back to their safe spaces on Parler or wherever. So much projection from the 8chan kids. Who cares.