This might've be mentioned before and I missed it, but could the next pack be climate based?
Completely unrelated to the PZ I happened upon this climate classification, lemme copy/paste the name from Wikipedia: Köppen–Geiger climate classification
View attachment 358834
Here's a quote from same page:
-"The Köppen climate classification divides climates into five main climate groups, with each group being divided based on patterns of seasonal precipitation and temperature. The five main groups are A (
tropical), B (
arid), C (
temperate), D (
continental), and E (
polar)."
Last two packs were called Tropical and Arid, specifically, not Rainforest and Desert or in spirit of "-lands" trend, Woodlands and Drylands.
I'm perhaps reading way too much into it, it's just when climates were listed in such specific order, it ringed a bell