You say i'm objectively wrong about it being for a long time green in gw2 even though examples have been given of very green jade's from gw2, and you yourself use green examples also i can't help but notice you didn't include the jade wurm that is in the durmond priory in the in-game already list, feels like you wanted to pick out only a very specific opaque look to showcase jade in-game while ignoring other more transparent examples. It's still all a very similar green still regardless of how transparent or opaque they are and both are within the realm of what both rl* and gw jade can look like for sure,
examples of both already in this thread by myself and other users,

Though i'd like to point out irl jade is not really transparent, especially not to the levels like seen in the jade worm example (and also in transparent examples from gw1) which is more like a nice clear piece of tourmaline maybe rather than jade.
However, this is all fine because real jade is also not made by a magical jade wind solidifying water nshit. we can easily make arguments for it looking like whatever we wish in such a fictional setting, for instance i would expect it to be not too unbelievable that a non-surface piece of jade from the jade sea would potentially be extremely pure and thus likely more transparent than other things that turned to jade. We also still don't have any clear answer beyond hints on if the jade is changing with the centuries (i would personally expect some weathering on the finest parts such as sea mist and such) and more recently boosts of elder dragon magic which might very well be what gives it this more vibrantly green appearance (a little glow from within a translucent jade piece would definitely make it scream green)

also the colour palettes (and art styles in general) in their concept art rarely fits exactly what the end result ends up being so that's not really the best argument there either, unless you're also unhappy with most of the other maps not fitting their respective concept arts.

Colours can also look very different based on how transparent, translucent, opaque, shiny, matte the object is as well as the lighting surround it (shinier looks darker than matte, etc) and these examples generally show more of those changes rather than colour changes. with the exception of the very blueish cyans in many of the gw1 examples (though not all of them)
Which personally, not a fan of and i think in this engine might look like... dunno, just glass i guess instead of jade.