User blog comment:Eobard95/Arrow Season 6 - Two characters dying?/@comment-3221148-20170809145328

Well, Mark said this: ''“I’m going to give a very unsatisfying answer to the Olicity fans,” Guggenheim admitted, “which is that we sort of set Oliver and Felicity on a certain trajectory starting with 520, and you saw a little bit of it in 523. We’re continuing it. I will say that the events of the finale did throw a little bit of a wrench into their slow rekindling of their relationship.”'' Source: http://comicbook.com/dc/2017/07/24/arrow-olicity-season-6/

The finale "throwing a wrench into their relationship" implies that it has been damaged, but not irrevocably so. So, Felicity probably survives, but thinks twice about whether she wants to date a single dad with a son.