There has been a staggered release pattern from Games Workshop for quite some time now. Now it seems that Tau Firewarriors are temporarily out of stock, and this could mean that the new expected boxes are coming next week!.
It seems that the US site still has them, however, in the UK they are gone, and that often is where changes are done first. I would expect that if Fire Warriors are next, than we will see them gone from the US site later today.
via aracerssx in the comment section
breaking news, fire warriors are temporary out of stock. THEY ARE NEXT ^^