Disney reuses ideas just as much as they remake movies

Umm, no. Have you even seen both of these movies?

Natty Gann leaves her home to go find her father who left her for a job in Washington, she just happens to have a dog with her along the way who protects her, as most dogs tend to do for their owners.

White Fang is about a young boy who moves up to Alaska to work his DEAD father's gold mine and earn his fortune, and he befriends a wolf.

The only thing these two movies have in common is that they both contain wolves in them.

You Can't Stop the Signal

Some similarity. But it's crazy to call White Fang a rip off or repeat of Natty Gann. White Fang is a well-known and great book by the great California writer Jack London. If anything, Natty Gann was a rip off of that.

Isn't the idea of people befriending wolves as old as stories themselves?

Well, they did have a railroad and an unhappy child scenario at the beginning of another Disney film (Flight of the Navigator) which to my surprise included a location suggestion of mine - the scout was dissappointed with the natural lighting at a certain location, and, at his asking I suggested another, which I found out later was accepted, and is seen in a sizeable portion of that film (I'm still waiting for my check - LOL), but, Navigator was fairly unique (though it was thought Disney was using ET as a springboard), but, in all fairness, it must be difficult to come up with new and unique ideas for film, since most scenarios have already been considered in some way...

In fact, a few years ago, someone in acting (I forget who) mentioned that there are only 7 general topics that are the basis for all stories, so, screenwriters have a tough job when it comes to being unique...