I would definitely welcome it.
I'm sure all of us have encountered music where that low A is called for. I hate having to transpose the melody up a whole octave or, if I don't do that and instead play just that A note an octave up - it sounds "ok" sometimes, but to me it's just wrong.
With traditional Bb to F keywork, the current dedicated-key range of the tenor sax is concert Ab2 to Eb5.
Giving the tenor a low A and a high G would extend its range to cover the full bass and treble clefs: concert G2 to F5. Such keywork for the high G might also allow for better altissimo combinations.
Even with a low A and high G, such a tenor sax would still fall short of even the alto clarinet (Gb2 to Eb6), which to me has the ideal range.
I've wondered, though, whether saxophone design has matured - we don't have some of the interesting key mechanisms we used to have. That we haven't seen much in changes (other than high F# on tenors and altos and high F#, G on sopranos) may be because innovation costs money and is risky and the manufacturers want to stay with a known, proven, design.
Yet, as competition becomes more fierce and profit margins dwindle, having something like a low A might be a selling point - even if only an option.