I don't know about rush, but there would most certainly be SRO for Evan Hansen. Great Comet feels like a show where SRO could potentially be a hindrance to the show, based on how far back on orchestra level the revamped stage goes. We won't know till they release more information though.
Either way, if you really want to stand in lines, there's the cancellation line which is still full price ticket. You could consider paying $49 full price for rear mezz seats for DEH - since it's in Music Box now, the sightlines would be pretty good.
Caption: Every so often there was a rare moment of perfect balance when I soared above him.