true but naruto has blonde hair, so that doesnt hold too much weight on wether or not hes an uzumaki.
Its not his blonde hair, or blue eyes that make him a Uzumaki. yeah he got a lot of his looks from his father, but has the chakra it seems that is compatable with suppressing the part nine tailed beasts chakra sealed within him like his mother the Uzumaki.
During the removeal of his seal and the implmentation of his own. If he wasnt a good host or compatable the biju would have been sealed in the temple till a new jinjuriki would be found.
Dose it mean that gara is a Uzumaki, no. There a finite (numbers of ways) way to list the ways he could and couldnt be. Or have some relation to a Uzumaki clan or the Eddy Village.
Could he have some wierd tie to the Uzumaki clans ancestors maybe. I mean even the sand village had to have some type of sealing juitsu to create their jinujuiki. No one knows the whole history of either the Sandvillage, or the Uzumaki clan of the eddy village. So as long as those are not disclosed there is a remote possibility that it could be possible.
If your talking about statistics and numbers the chances of being struck by lighting are slim to none but it still happens, the chances that you win the lottery are probabaly smaller than that but still people win the lottery. Is there a possibility that Gara or the Uzumaki clan or any of its ancestrors or the decendants of the Eddy village yeah Im sure there is one I couldnt give you a number to say the specifics about it though.
Lastly not all questions like the thread of the title have just a yes or no awnser, theres also maybe and maybe not. I kinda think their bull crap awnsers but its still a choice and valid as anyone elses oppinion/idea.