Hmm, not sure how you've read "sex with women damages their future relationships" from the article.
Partner count is directly tied to infidelity risk in women, this is definitely true. The more men a woman's been with, the less likely she is to stay faithful. The more divorces in a woman's past, the more likely she is to divorce again in the future, too. I haven't seen any research on it (and doubt it exists), but I'd imagine number of lifetime boyfriends also increases a woman's odds of ending a future relationship... the kind of girl who jumps from guy to guy is also more likely to jump to the next guy.
Beyond that though, I haven't seen much evidence of women's sex partners damaging them much for future relationships, unless those partners were abusive, or set expectations they dramatically failed to hit. If a man promised her the moon, and she really believed it, then he did not deliver, and it was an awful end to the relationship, that will affect her future relationships: she'll be a lot more cautious, less trusting, and less giving. This isn't about the sex per se; it is about the nature of the relationship. Thus why women's past matters when you want a serious relationship.
In the manosphere, the general sentiment seems to be "sexual relationships with other men harm a woman's ability to pairbond with her future husband." This can be the case, but... it's much, much more complicated than the manosphere guys make it.
Maybe I'll do an article on this in particular. It's a prety fuzzy area and probably something to address in clear terms ("Are you damaging women's long-term potential if you have [sex|any other specific kind of interaction] with them?").
But in general, from everything I've seen, unless you do something insane to her, you're probably not going to have much impact on her future romantic relationships if all you do is sleep with her. Now, if you have a longer relationship with her, there's a lot more potential to boost her up or, alternately, ruin her for future men... but again, that's something to discuss in detail on its own.