I have a addon for java edition. This has the biome: [ Taiga Hills ]  to spawn Grizzly Bears, which are Ravagers. And when I had a world always Taiga Hills biome, there are no creatures spawning. So I can't have Grizzly Bears spawning as creatures in the biome. That may be because the experimental features are not supported as what it had said before. I wish there would be a feature in the game to continue without problems like these.

I am saying this as both a bug report and idea.