I fly pretty frequently for work and get upgraded maybe 40% of the time to first class and the rest of the time to the 2nd tier economy plus with more legroom. I always buy a coach ticket. That's a free perk for individuals that have obtained certain status. I'm just flying domestically in the US. These guys fly internationally quite frequently. Plus domestically. I would venture to guess most of them have qualified for the top tier frequent flyer status and would be at the top of the list for upgrades. Also, many companies (mine included) allow you to book business class for international flights.
Remember, this is a business. The GB are the top executives of a multi-billion dollar business. Many companies top executives actually fly a private jet.
I also think the expensive possessions are likely gifts from wealthy JWs to curry favor.
While it's hypocritical for them to have expensive suits while admonishing JWs to not go to college and not worry about having careers, I think it's way down on the list of terrible things they do.
I think criticizing them on things like their awful child abuse policies and dangerous blood policies is more effective. Quite frankly, no JW would care about their spending and no one on the outside would either.