They're not dictating what employees can do on their own time, only what they can use company resources for. You can always find a restaurant with good vegan/veg options, although its admittedly harder in europe.
So you fly away from your family to spend the night closing a deal for your employer and after a long day of meetings you sit down and have to order tofu because the latest Richard Hendricks of the hour started dating a vegan. Fuck this whole idea and fuck WeWork.
The purpose of expensing meals is to compensate employees for the greatly increased cost of eating that is imposed by travel taking them away from their normal food storage and preparation facilities. It shouldn't be regarded as using company resources to purchase food. It should be treated as a form of employee compensation.
Would you be so understanding of this rule if it was the other way around? If you were only able to expense meals including meat, and vegetarian options were carefully excluded at WeWork events?
I was a vegetarian for years and it fell apart when I spent 6 months as a music tour manager. When you are on the road you need to work with what's available. I support being vegetarian and even encouraging this among employees somehow, but maybe there's a way that's more considerate and practical.