Yeah... many discussions on ethics usually go this direction. I find it a pretty squishy topic because so much is personal, hard to define, and sometimes even nebulous. Lifestyles can be ethical or... they might not be. Diets can be ethical or... not. One could be vegan for health reasons alone and not have any ethical stance towards animals. Years ago, my problems with digesting dairy led me to stop eating cheese and other cow or goat milk based items. At the time, I did it purely out of a need for physical comfort. Only over time did I learn more about veganism and begin to have more of an ethical stance towards animals. For me, veganism does have a large dose of ethics in it. For others, that may not be so. I've taken too many ethics classes in the past to go much further (I was a philosophy undergrad). Though fascinating, it can lead down many rabbit holes and dead-ends with difficult to prove or resolve arguments lurking along the way. In any case, it's worth having the discussion, but any resolution will likely not be forthcoming.
Lastly, it looks like the prefix "ovo" only really applies to vegetarians, not to vegans, so one can't be an "ovo-vegan?" I have heard of "ovo-vegetarians," however.
Lastly, it looks like the prefix "ovo" only really applies to vegetarians, not to vegans, so one can't be an "ovo-vegan?" I have heard of "ovo-vegetarians," however.