That's quite a narrow definition of politics. I'd say anything that humans do that is perceived by others to be part of a social structure that maintains or challenges social norms and power relations is political.

Only if veganism itself becomes something nobody would challenge (like health is better than death, breathing is important) or if you are the last person on earth you can become the first apolitical vegan.

I mean they literally inseparably related to political policies so yeah I think they're political. How can you separate the lgbt movement from gay marriage or civil rights? How can you separate veganism from ag-gag policies and the laws around modern day factory farming. I mean as a vegan and a gay person I don't understand how they could not be perceived as political. Sure its sad that people are against gay rights and stuff but its certainly political.