Poppy fields exist, are beautiful, and could be a very different vibe than regular flower plains biomes. A large landscape of red poppies have always inspired me and I believe in Minecraft people would love to build houses by/in them. A vast red landscape could be a really bold contrast to the grassy plains. Maybe a stretch but they could potentially be used for massive bee farms in the post/late game. Plus it’s just a great way to take what’s in the game and make a little nice filling addition to the wild update. If that’s not enough you could add butterflies that spawn in them or give them specific music, but I’m just spitballing here. Maybe the alley could find treasure in them that perhaps you couldn’t find yourself. Or just regular poppy fields the would be lovely and atmospheric even with no other additions to it.