Deleting Named Pipes When Closing
It is neat and tidy to delete the FIFO, but it is not crucial to do so. In particular, the FIFO will be empty when the system is restarted.
So, it is best to design your programs to accept the presence of the FIFO, and to create it if it is missing. If they get closed down cleanly, then removing the FIFO is good.
I haven't used them for years, but I am about 80% sure you can leave the nodes in place forever. And they'll be empty on bootup, because the data is held in kernel data structures.