I have now made far more than the necessary testing to state this with 99% accuracy.
Rarity on creation has been stealth nerfed, to somewhere between 20% and 33% of the original values.
or they just messed up something making it become like this
It doesn't create a non-rare item, but you just get significantly less moments of inspiration when creating an item (at least a 2-component garauteed-rare one)
Please keep in mind that i have made over 600 rares and 80 supreme items in the old