Depends on the tree. Some trees are affected by Black Walnut toxins, others are not. The toxins will still be in the soil, but the root competition will be gone. What is your Zone? What are the site conditions? With more information we may be able to recommend trees that can handle that situation.

A redbud or Black Cherry would do fine.

If you are planting a maple, you might want to lime the soil, add compost, plow it, and wait a few years.