If we’re getting technical, wall-charging is not an exploit. Generally, to exploit something is to take full advantage of a resource or opportunity. Even as a noun, it’s generally paired with a negative or malicious connotation. Very often when we use the term to talk about games, we broaden its definition to include taking (full) advantage of an unintended feature.
While I don’t think the designers consciously thought up wall-charging, I do think it’s all a part of hit box interaction. Consider how monsters can get stuck on pitfalls when pulled with Rage Flip, or how WW Barbs can “stick” to certain walls. Consider how Twister Wizards used to “stick” and stack twisters. Only one of those was fixed because players used it to break the game–at the time, anyway.
Wall-charging doesn’t break the game, or even a GR, in the same way as the bug pack does. It allows you to maximize Endless Walk’s bonus, but to me, at least, that’s indicative of little more than EW’s design not accounting for all the variables in hit box interactions.