In general, "ceding the floor" is good practice in open forums like this one, even if you don't know if you're interacting with marginalized groups (and even if you're a member of a marginalized group yourself).
That's something everyone occasionally screws up, especially in an online forum where everyone can be typing at once, but it's also something that, if you can force yourself to slow down and listen, to let the silence linger between the last person's response and your own, to pause your contribution to let other voices be heard and then acknowledge them, the value of the discussion overall will improve.
It's one of those lessons that everyone, not just white cis men, can benefit from--but often it's a lesson that most needs to be learned by people who don't fully recognize the space they occupy, which is a mistake that is most frequently made by white, cisgender, heterosexual men.