One of the main goals for Tales of the Valiant has ALWAYS been to remain compatible with 5E!
For some reason, some folks got the idea (or in some cases, just a personal wish) the ToV was going to move away from 5E, or be an entirely new RPG ... but those were never stated goals for Tales of the Valiant.
The point is to be able to play Tales of the Valiant and use any of your existing 5E material you want (Kobold Press 5E material, as well as other 5E)
Many people have compared what Tales of the Valiant will be to what Pathfinder was to D&D 3.5, and, while not a perfect analogy, it's a pretty good one