Current map I am on has been interesting.
First island has all biomes except plains.
Mountains with silver next to swamps with iron ... previous maps I have had almost never seemed to have this combination but I am finding multiple sites like this now on this map.

This may be due to crypts spawning in swamps they normally wouldn't before.
Typically if you had a strip of swamp you could pretty much know there were no crypts there. I have played a lot of different random maps and even posts on the forum would indicate as much.

But this map I am on now it does not seem to be an issue.
Did things change with the last update?