Resolves YES if strong evidence comes out that Neil deGrasse Tyson went vegan, for any reason, before 2030. An example of strong evidence is him announcing it publicly.
More specific criteria:
He has to be vegan for at least 30 days continuously. The 30th day must be before 2030.
I'm only counting eating foods that are typically considered vegan, not additional things like avoiding leather or animal-tested cosmetics.
At least 95% (by volume) of the food he consumes must be vegan during this time. Rare exceptions are not enough to cause the market to resolve NO.
To roughly point at the cutoff point of what I'll consider vegan for this market, I'll give a few examples. Meat, fish, dairy, eggs, honey, and insects are not considered vegan. Lab-grown meat, cane sugar processed with bone char, vitamin D from wool in cereal, and foods with minor contamination from animal products are considered vegan.