It would be a major letdown by EK if she would make a scene like this. It is very clear that wild Holly became slutty due to missunderstanding Ian´s taste in women (at least partly since we have several versions of Ian). Her finally getting Ian is exactly what she wanted when she started to "slut it up". So all or most of the influence slutty Lena and Ivy had on Holly will be gone.
She´ll still be friends with them, no doubt, but the influence on Holly will depend a lot on our decisions how Ian reacts to wild Holly. If they go to a full dedicated, exclusive relationship, Holly will keep her wild side for the bedroom, but that´s it. If they go for a full dedicated, exclusive relationship with Ian really liking her slutty side, they might experiment a bit, but nothing major.
And in the case they go for a dedicated relationship, but Holly having not missunderstood Ian´s taste in women, she, Ivy and Lena might still go really wild because this variant of Ian´s likes it justlike that.