When using a seed with the Large Biomes generation setting in 1.18 pre-release 1, it will not match the biome placement of the same seed's default generation. The biomes on the Large Biomes world seem to indeed be larger than usual(though there is no way to compare directly), but the terrain and biomes will be completely different compared to the default world generation using the same seed. The player will typically spawn in completely different biomes when using the same seed to start new worlds with the default and large biome settings.

Seeds Tested:

2750910098977602618

4699348471075164823

How to Reproduce:
Create a world using default generation settings.

Create a Large Biomes world using the same seed as the world with default settings.

Compare the biome placement of each.

The biomes on the Large Biomes world seem to indeed be larger than usual(though there is no way to compare directly), but the terrain and biomes will be completely different compared to the default world generation using the same seed. The player will typically spawn in completely different biomes when using the same seed to start new worlds with the default and large biome settings.

Expected Result: The Large Biome world generated from the same seed as a default world would have the same biome placement as its default generation, only larger. This is how Large Biomes functions in 1.17, 1.16, etc.