Any company that is concerned about their PR image has to do some filtering of this sort, otherwise they get hit pieces like [1][2] though in both cases, it was (aggregate) human behaviour that was beneath said issue.
[1] https://www.wired.com/story/google-autocomplete-vile-suggest...
They do not, in fact, have to. They choose to. Don't ever let parties off the hook for choosing to do something just because they claim to fear PR blips if they don't.
I just don't get this logic. It's a keyboard, after all. It's meant for typing. It's like if my camera refused to take a picture of my butt because it might offend someone.
The answer seems obvious to me: train a user’s predictive swipe engine on solely their own messages. It gives them an easy out on controversy while removing the need for a filter list.