That depends if it meets the minimum requirements of Ubuntu Phone OS:
Operator and OEM partners | Ubuntu for phones | Ubuntu
Looks like Ubuntu needs an A9 Cortex CPU and the Pre2 has an A8 Cortex, according to wikipedia:
Palm Pre 2 - Wikipedia, the free encyclopedia
I'm not sure, but I think it's not going to work.
[edit] I don't think Ubuntu supports the hardware keyboard.