Sponsorships, gofundme pages, and the like are actually fairly contentious in the AT hiking community. Some people believe that the AT is a life goal, some massive undertaking similar to summiting Everest or something, while others (usually those who have actually hiked the trail) consider it closer to a vacation, like going to Disney World with fewer children.
As such, any discussion of fundraising will always start a fight on the various web communities surrounding the trail.
However, there are some companies that will sponsor hikers on their thru, provided the hiker asks first. Some sponsorship offer gear, some offer money, some will send you food of coupons, and so on.
I have contacted a few companies for sponsorships, some who regularly sponsor hikers, and some who don’t, in an attempt to make certain aspects of my hike easier. So we’ll see how that goes. If I do get the support I was looking for, yay! If not, I have no hard feelings for the company.