I think you are talking about marriage and family, more than just sex, right? Because sex-wise, you can do what you want already.
Polygamy no. I don’t think that’s what most people want, the sister wives thing. That’s a system used when men are scarce and you are trying to increase the population quickly, neither of those conditions exist now, and polygamist systems are often dead patriarchal and nasty.
Polyamory? The make your own family, whatever configuration, more than 2 people? I think we are closer to that, yes. In a time when you are trying to decrease birth rates, yes families with more than just a couple might become popular. More parents to love and care for each child would be handy.
Polyandry, two or more husbands? That would work in a world where there were more men than women - but most of those places in the world right now are not places where a woman would have the freedom to do that.