I'm just a student of music and the bass and would like to know what the truthful/music theory answer to this is.
The definition of a chord seems quite fundamental to me. Why the controversy?
Because not everyone agrees on definitions, and things change over time. Music theory that doesn't represent actual practice isn't that useful, is it?
A "two note chord" is generally not considered a chord, because it's an interval, and can only imply a full chord.
But if you live in a world where that ambiguity is considered a
feature and want to treat a power chord as a chord despite the missing 3rd, that's fine. After all, there are plenty of "real" chords -
diminished chords, I'm looking at you - that are still ambiguous but accepted as chords. People use power chords every day,
without wanting to add the 3rd in, and don't consider it missing.
The overtone series will cause a major 3rd to be created via sympathetic vibrations anyway.

So if you want to call it a chord, fine. Just be aware that's not the definition accepted by
most people, and don't lose any sleep over it.