C4 as 440Hz (1) seems highly unlikely. Tuning standards have changed a lot over the years but it is fairly fixed today (outside period ensembles). The saxophone is a relatively new instrument and won't appear in these period ensembles (unless it is imitating an unavailable obsolete instrument).
There is a complication with the saxophone which is that it is a transposing instrument. This means that when you play a specific written note, e.g. middle C, you actually get another note. Which other note depends on the particular saxophone.
In the following cases, suppose that the player sees a written middle C.
Soprano - This is pitched in Bb which means that it actually plays a Bb. In this case, the one just below middle C. A major second below.
Alto - This is pitched in Eb so it actually plays an Eb; the one below middle C. A major sixth below below the written note.
Tenor - Also pitched in Bb but it plays an octave lower than the soprano. An octave and a major second below the written note.
Baritone - Also pitched in Eb but it plays an octave lower than the alto. An octave and a major sixth below below the written note.
An advantage is that a player can swap between instruments in the family and use the same fingerings for the same written note even though the note produced will differ.
A disadvantage is the composer, arranger, or conductor must adjust. Suppose that there is also a piano and its part is written in F then the parts for the soprano and tenor saxophones will need to written in G and the parts for the alto and baritone will need to be written in D. Alternatively, the player has to transpose while reading. This is a skill that players of transposing instruments often develop.
Back to tuning. Suppose that you are tuning against a piano or oboe playing A4, the soprano and the alto saxophone will need to play a B (not necessarily B4) and the alto and baritone will need to play an F#.
This still does not explain the C4 = 440Hz.
We could look at the clarinet. There are a few common versions.
Bb which like the soprano plays a second below like the soprano saxophone. This is the most common clarinet especially outside classical music.
A which plays a minor third below unlike any common saxophone. It will need to play a C to tune against the piano playing an A. This version is not common outside classical music.
Eb which plays a minor third above the written note. This is also rare outside classical music.
Bass clarinet, usually in Bb playing an octave and a second below like the tenor saxophone.
So, if a clarinet in A plays a written C then it should produce an A and hence, by modern standards, 440Hz. However, to get an A4, it would need to play C5.
No common saxophone is pitched in A so it is it hard to see why any of them playing a C would produce 440Hz.
The only other instrument pitched in A that I can think of is the oboe d'amore. It is not very common in classical music and, as far as I know, unknown outside classical music.
(1) Normally Hz for Hertz. I was puzzled at first by your HZ. Scientists can be fussy and the case of units is significant and can make a big difference.