puts() works but printf() does nothing in TI Code Composer Studio with MSPM0L1306 launchpad

I/O is usually buffered.
It is flushed automatically when either the buffer is full, or a newline is encountered (more info here: What is it with printf() sending output to buffer?).

As you can see in puts documentation it adds a newline:

Writes every character from the null-terminated string str and one additional newline character '\n' to the output stream stdout

^{(emphasis is mine)}

On the other hand printf does not add a newline, which explains why you don't see the output (being still in the buffer).

To solve it either add a newline:

//------------------------------vv---
printf("Yea, we are running now.\n");

Or manually flush the stream after the call to printf with fflush:

fflush(stdout);