I don't think you intended to create that impression, but I didn't go looking for it either. It's created by phrasing like

> In this post, I’ll be presenting an alternative to the traditional strategy of manual memory management that I’ve had success with: the arena allocator.

and

> My approach, on the other hand, is this: instead of assuming that malloc and free were the correct low-level operations, we can change the memory allocation interface...

Together with a complete absence of any reference to the history of the technique or any of the people besides you involved in its development.

It's not an accusation, but it's a clarification worth making as I genuinely think someone without knowledge of the subject could come away thinking you were presenting your own innovation.