User1751825 gave what I think is the correct answer: Don't worry about it.
At 2 years old, most children can say sentences with 2 to 4 words, and may have a vocabulary of only 50 words. A long list of alphabet letters is still a very abstract concept, and it is totally okay if they aren't getting all the letters, or aren't saying them in the right order.
Relax and enjoy this time. Don't spend it worrying what this might mean for their future development. It's adorable. Make sure you get a video of it so you can watch back on it someday and laugh.
Finally, I think user1751825 also hit the nail on the head with the advice: just model correct behavior. Don't correct the language at this point. A dear friend of mine grew up always being corrected, and it made her shy and not want to say anything until she was sure she was right, and wasn't going to get corrected. That's no way to raise a child.
Man I wish I had more videos of my kids at that age making those adorable language "mistakes." :)