I have no problems with any of the characters on this list. I thought the MKX characters all deserved a second chance, so I'm actually okay with Jacqui and the others being back. I want more 3D characters, and while I do think Frost is an odd pick over Sareena, Fujin, Havik, etc, overall I think she's an okay pick.
My main problem with the roster is that Shang Tsung isn't on it (yet), and some characters that should be in since others are, are well, not here? Like Cassie and Jacqui is in but not Takeda? No Takeda OR Kenshi? Even if Takeda is a surprise character, then that means 3 of the kombat kids are back so why not Kung Jin?
Also if Sonya and Johnny are in and we are still getting Cassie, then where's Jax? He's been in almost every MK game since MK2 so it would be weird that he's left out, especially since MK11 seems to take some inspiration from MK2.
Overall I think the roster is good and I prefer it over MKX's launch roster, but it's certainly a weird line-up right now... Maybe there's one or two more characters not of the list yet that will tie everything together, maybe some of the new characters will explain why others are not here, and maybe the Kombat Pack will have some that couldn't make it in day one.