Yes, you will come in contact with some fecal matter.
I want to personally assure you that that you will not poop on anyone during anal sex. Sure, there are horror stories, but aren’t there always?
I also don’t get why someone would want to save the bad stuff until last to ‘avoid putting people off’. Why exactly do you want to encourage them other than for men’s sake. The majority of women have never tried anal sex and it’s only in the past few decades that it’s become more common among heterosexual couples. Even then, for most, it’s not something people do regularly. Mainly because for most women it doesn’t do much and can be pretty painful.
As for the stuff about poo. Yes, you’ll come into contact with poo, but I can promise you won’t poo on anyone? How can you promise that? How do you know how other peoples bodies will react? And surely someone getting your poo on their penis isn’t that different to you pooing on them? Also some men engage in disgusting practices like switching between anal and vaginal sex without warning and without cleaning up first. That can cause pretty bad infections for women.
While anal prolapse is a rare thing, fecal incontinence is not and the risk is doubled in women who have anal sex and tripled in men. I don’t think I’d be up for that for something that doesn’t do anything for me. No way would I make a health sacrifice like that so that a partner could have a bit more ‘tightness’.
I don’t think pointing out the realities is homophobic. You can’t put anal sex and vaginal sex as having completely exactly equal risks because that just isn’t true, as the anus was not designed to be penetrated with hard objects and you have to be careful as a result. At the same time, you can point out that lesbian sex actually carries a lower risk than both vaginal and oral sex. As usual, most of the activities listed in that guide are ones mainly preferred by men and lesbians are left out. If you really want to be safe girls, date other girls and leave the blokes with their demands for anal to their own devices.