Q.Spring Snow crabapple produced many root branches
Several years ago we had to cut down (to the stump) a our 15 yr old spring Spring Snow (only to the stump level with the ground). The following summer we saw many root branches growing from behind the stump. Because we planted this tree in honor of the birth of our 1st child, we are sentimental about it. Since the leaves looked healthy, we decided to tie 6 of the thicker branches together and just waited it out. 10 yrs later those branches are a strong healthy 30 ft tree but what is really amazing is that 5 years ago it stopped producing white flowers in the spring and began producing white/pink flowers that grow into an abundance of delicious wild (cooking?) apples! Can you share if this has happened before to other Spring Snow crabapple trees?

Your tree most likely was a grafted tree. When you cut it back the original root stock began growing and this is the tree you now have.
Your tree looks amazingly healthy and looks like your enjoying a wonderful crop of apples. Enjoy!
Thank you for sharing the story behind your tree.