Quick question: who/what are the creepy statues on Ilos?

Yeah I'd say they were retconned in, which is fine. All those tentacles look bizarre and would have been a pain to animate.

Before ME2 was released, the wiki showed those statues , tentacles and all, looking like husks, under the Prothean description. In fact, I'm pretty sure the in game codex shows them as such in ME1. The wiki has since been modified to claim they were 'Insuannon' all along.

It's similar to what they did with Qunari in Dragon Age. Once they managed to figure out how to represent how they intended Qunari to look, they retconned Sten to being a special hornless version of the race, etc.

Yeah, I have this "Kaidan must go to EP" thing running in my head.  I feel like the devs really missed how much sense this makes.  I suppose it could have worked differently had From Ashes been part of the base game rather than DLC.  Could have been first stop after Mars (or even instead of Mars) where Javik is found.  Could have even worked to have Liara found there and at this point A/K is injured and sent to the Citadel for care.

I can't help spinning out ideas like this.  It's a character flaw.

Yes because they didn't have any idea what Protheans looked like.   They were like the Forerunners in the Halo games up until Halo 4. Very little solid information and no idea of their physical looks, just slight tid bits of information and artifacts of super advanced technology.  And when Mass Effect 2 was in development the revelation that the Collectors were Protheans was a late in development change.  Because the Collectors were Protheans when designing Javik they had to use the Protheans as a general base model to start with.

The whole development of the Protheans both visually and lore wise with this trilogy was kind of a cluster fuck.