Why 2022.1 snapshot didn't support 1.18.1?

if (1.18.1 == 1.18.2) {
    !1.18.2.exists();
} else {
    1.18.2.addMajorChanges();
    1.18.1.setOutdated();
}

Hello, so if I understood correctly it is impossible to create a mod in 1.18.1?

Yes because it isn't supported in Mcreator

@PetitPrince It is possible to create a mod in 1.18.1, with code. If you want to add some simple things, I'd highly recommend KaupenJoe, he explains quite well how to do it.

As Goldorion explained in Java syntax (XD), 1.18.2 introduces huge changes in registry. Therefore team had to decide:
- whether it's better to make it for 1.18.2
- or to make version that is already outdated and will need a lot of changes, just to leave it right after publishing the snapshot (so the snapshot would be for nothing, because there'd be feedback for already non-supported generator)

Quite easily understandable that the only wise decision is to make 1.18.2 mod. Don't worry - 99% mods that has 1.18.1, will make port into 1.18.2. Just not immediately, since new code is confusing.
But... MCreator will be able to be there! Even faster!

So the decision itself is really awesome, because it makes MCreator finally stand out from coded mods with such one, simple trick. Just by supporting generator which will take coded mods quite a while to port over.