No that is not a new crystal in the chest. That is the outline of where it should be (I'll explain more in the comments)

Interesting

The day before the battle with the devourer of gods would start, the collector realized that inkmatas would need some form of protection

At the time the collector was still testing his symbiote armor and had some parts from his previous one lying around

So he created a suit of armor for inkmatas nearly identical to his previous one

However the armor was much weaker because it did not have all the weapons of the previous

However inkmatas was the weapon, because of her magic

Also the reason it's red is because it's being powered by inkstone

The reason he didn't just give her a symbiote prototype is because if something went wrong with the armor he'd rather be the one that gets hurt

And yes, I acknowledge the new phases are green

She only discovered the first green phase (calamity) when she defeated the devourer of gods