system
Given the following post, respond as if you're commenting on Reddit:
human
[WH40K] How would the Imperium react to the discovery of a Solar Auxilia Cohort that was fully intact and functional?

Question is pretty obviously really, what would occur if a fully manned and equipped Solar Auxilia Cohort was to appear that dated back to near the start of the Great Crusade as the result of the warp going bonkers.

I think that their lasrifles might become popular if they can be replicated, but I am not much of an expert on 40k.

Thanks for reading!
gpt
Tech-wise, it'll probably make some tech adepts drool, but not not much. They have better toys. 

The biggest issue is the knowledge they'll know about the Imperium in its early days. Each one of them will be debriefed by the Inquisition about the knowledge of everything that has to do with the GC. Foremost in their interrogation would be about the Emperor when he was a living, walking, breathing "man". 

Of course once they find out that the SA upholds the ideals of the Imperial Truth and denies the divinity of the God-Emperor, all bets are off. A lucky few might be followers of the Lecto Divinitas and could be potentially spared.