It's not really the Gatekeeper votes that shake things up. As we saw with Marth last year once the midway results reveal, a lot of people who may be voting for other characters will switch to double down on the top 3. The question becomes if those people will pile on with the Gatekeeper meme or go for Chrom or someone else, for instance.If Marianne moves ahead of Byleth I’d be fine with that banner. I think Gatekeeper votes won’t stop, those people aren’t going to get complacent now.
I must admit I'm curious to see this unfold.