I mean, this is worse to me. The 'river to sea' chant seems to be used by two different crowds, as it's simultaneously used as a generic slogan for liberating the Palestinians and an anti-Israeli slogan. I think a lot of the people joining in the chant at peace marches probably haven't ever studied a map of Israel and Palestine and the River Jordan and considered its implications - they just want the Palestinians to be free and have their own state - and so it's not an intentionally hateful statement in a lot of their cases (even if, in outcome, that's clearly how it will legitimately sound to many Jewish and Israeli people, and people should probably educate themselves before chanting things).
'Kill all of them' lacks any such ambiguity in intent.