Hmmmm I don't think "egalitarian polyamory" is necessarily ethical. In that, while it's not necessary to ask "permission" to date someone, open communication is still important because each person in the relationship has equal rights and the ability to set boundaries for themselves. So if someone has the opinion that "I can date whoever and never tell you before hand and let you have the opportunity to set your own boundaries about it" then they're disrespecting you in the relationship. Your potential boundaries don't matter to them.

Like, yes I believe that in polyamory you can negotiate boundaries across time, so you can say "hey I want to date so and so, let's talk about this" but it's not so much about "asking permission" it's checking in with the person you ostensibly love, and making it clear to them that their feelings matter as much as yours, giving them the opportunity to express their boundaries etc. And if after all that they say "no" then that's a valid boundary and you can then respond with either going ahead with it, or ending the relationship to pursue the new person.