I doubt this. Majority holders are probably not yet aware of this poll. If we make an effort and make them aware and win the poll, then Blockstream might back out again and say "bitcoin is not democracy", "mere winning wont do, you need 90%+" etc.
You can't expect everyone in the ecosystem to vote on a poll, that is absurd. You try to get as many people as you can and then draw to conclusions. You have the link now, go try and find these 'majority holders' that are against it. As it currently stands there is more than 80% support for Core.
So, there needs to be clear message from Blockstream that they'll move to 2mb if they lose this poll 51:49 and give us three months to send the message across.
This would be a split, not consensus for 2 MB blocks.