I heard a quick response from a Rav, who said it is not a psak:
Q1: boycott? We have history of boycotts usually when the price is outrageous – fish on shabbos. A couple of gemorahs where Rabonim threatened merchants that they will rule according to a minority opinion (what hadasim are kosher, etc) to ruin their business if the prices do not go down.
Q2: should one destroy ice-cream in his freezer? It is not hurting the company, even if you post the picture of that on twitter, and there is bal tashlis issue. Maybe, only if you physically feel like you are eating treif …