Does improving animal rights now improve the far future?

80000 Hours says, “We think intense efforts to reduce meat consumption could reduce factory farming in the US by 10-90%. Through the spread of
more humane attitudes, this would increase the expected value of the future of humanity by 0.01-0.1%.”

I’m having trouble understand reducing current meat consumption would increase the expected value of the future. I’m not entirely sure if by spreading humane attitudes 80000 Hours if referring to current humans having more humane attitudes or far-future humans having more humane attitudes. Also, when it says “humane attitude”, I’m not sure if they actually mean changing people’s terminal values to be more humane or merely being more humane not by changing their terminal values but by getting place higher value in increasing animal rights by better informing them about how bad they are.

If it’s referring to making current humans more humane without changing their terminal values, then it’s not clear to me how that would improve the far future. People in the far future could presumably have plenty of time to learn on their own what damage factory farming causes if for whatever reason factory farming is still in use.

If it’s referring to making current humans more humane by changing their terminal values, then it’s not clear to me how this would occur. My understanding is that animal rights activities tend to spend their time showing people how bad conditions are, and I see no mechanism by which this would change people’s terminal values. And if they do change peoples’ terminal values to be more humane, and this is what people would like, then I don’t see why people in the far future wouldn’t just change their terminal values to be more humane on their own.

I’ve look around on the Internet for a while for answers to this question, but found none.