its pretty simple, war is a sensitive and divisive subject. celebrating the veterans of one country can be disrespectful to people from the country on the opposing side. imagine a scenario where bungie celebrated US Veteran's day with a splash screen and a number of people see it who had loved ones killed by Americans in war, they wouldn't be so happy to see that splash screen would they. And vice versa, if you had a loved one killed in a war would you want to see a splash screen celebrating the veterans of that country?