Yes - [It's a given, it's obvious to Thor that this should be done] - because having a warning is better than being caught unawares.

[He uncrosses his arms, taking a breath to keep from retorting over Loki's continuing derision over Vision.]

But more than that, so I can know what it is you're warning me about.

[Years have passed since Thor's visit to the Norn cave. It's branded in his mind but no amount of searching and questioning across the universe lead him any closer to answers. Now Asgard and Earth might be on the line if whatever's moving these forces closes in on them. And Loki has been one of those forces.]