You are very welcome @anil!
Helping people and talking about gear--this is what we love doing! Also, I have some news regarding the tires. I actually reached out to one of our cycling technicians to better explain why one model is "tubeless ready" and the other is not.
So, both models are using the same tires (Schwalbe CX Comp) and same rims (Cannondale CX 2.0), but the '20 CAADX 105 is "tubeless ready" because the rims had been pre-taped by Cannondale. With that being said, it's a fairly simple process to have the rims taped on the '21 CAADX 1 if you wanted that bike to be converted to tubeless as well.
I am very sure either one of these bikes would be a great purchase and an absolute joy to ride. Let me know which one you end up with, and feel free to reach out on any future questions!