Basalt delta near my portal turns into crimson forest?

Near my first portal that I've made to the nether, I've spawned in a basalt delta which has been a normal basalt delta, and worked the way it should. When the 20w28a update hit, my basalt delta has transformed into a crimson forest. It looks like a basalt delta, but piglins and hoglins spawn now and the sky is red, like in a crimson forest. Which is really weird, I don't really know why this happened.