I think it's great that the devs have brought back a classic, though modified, creature from TOS. There's one problem though: if these creatures feed on copper based blood, they might want to chase after Andorians.
Copper based blood is blue, like that of an octopus, or possibly an Andorian. But Romulans, as well as Vulcans, have green blood, which means their blood is sulfur based. Even in the numerous Star Trek novels and information websites, Vulcan and Romulan blood is recognized as sulfur based. Please make the correction.
Vulcan blood and by extension Romulan blood was always known to be copper-based. If Star Trek used any science in blood color, then copper "rust" looks green just like iron rust appears red. Old buildings that used copper for their roof look green. So if you are correct in your assessment, then the people currently in charge of Star Trek would need to make the correction not Cryptic since Cryptic is going by what Star Trek has stated.
Vulcan blood was copper-based and was copper- or rust-colored when deoxygenated in the veins and green when oxygenated in the arteries (although it is unclear if this transport mechanism was a hemocyanin as in Earth molluscs). Bruises and dermal abrasions took on a greenish color. (TOS: "The Naked Time", "Patterns of Force"; DS9: "Field of Fire"; VOY: "Repression"; ENT: "In a Mirror, Darkly, Part II");
The problem is that it's more important in fiction to be internally consistent than correct. Since it's already been established countless times that Vulcans and Romulans have green copper-based blood, any future Vulcans with blue blood, while being more accurate to real life, would break ST's own canon and therefore break the audience's immersion.
Just pretend ST takes place in an alternate universe where hemocyanin is green instead
The simplest explanation is that since The Original Series stated that Vulcans' blood is copper based and green when exposed to air, then it is established canon for Star Trek.
That's the presumption that they used in TOS when they were creating the explanation of the green blood. Just like iron oxide (rust) is red, similar to our iron-based oxygenated blood; copper-based oxygenated blood would be green, similar to copper oxide (copper "rust").
Okay, it looks like I'm half wrong, half right. Memory alpha and beta stipulate copper based blood. My mistake. But there are some conflicts as well. In the ENT novels The Good That Men Do through The Romulan War part II, Charles Tucker, working undercover disguised as a Romulan, has to keep taking sulfur peptide drugs, or something like that, to keep his blood green. That, and copper based blood really is blue. Look at the wikipedia entry for Hemocyanin. Sigh; it looks like I found a flaw in the Trek-verse. Oh well. I'm still looking forward to battling these ugly things.