Yep, I got this email this morning too. I'm also travelling next week

There's nothing on Covid.is or the Icelandic government website that mentions this. I also downloaded the Rakning-C19 app and can't see anything on that either, although the "Information for Tourists" panel doesn't seem to have an active link to anything.

https://www.covid.is/categories/tour...ing-to-iceland

This either looks like a pre-announcement (in which case I imagine it will be starting at a later date) or a mistake.