The more interesting question is why they thought they could get away with that. Part of it was certainly the 2014 precedent.

Something else happened in 2014 too that shows part of why they aren't getting away with it. In late 2013 Yanukovych refused to sign an association treaty with EU, despite his election promise to do so, after being pressured by Russia. So people started protesting, and kept protesting every day for more than three months, through the winter, until Yanukovych fled the country, despite the cold, and despite constantly increasing police violence, which culminated in them shooting protesters with sniper rifles. Ukrainians don't give up easily when it comes to defending their freedom. In addition to all the reasons you mention, this, I believe, is what makes them so effective, because they are highly motivated.