One Arduino and Two computers?

Hello! I am making a drum kit by utilizing a raspberry pi (as a midi host) and an arduino uno (as a a medium to sense piezoelectric sensors and send appropriate midi data through usb cable). I have flashed the 16u2 chip with the HIDUINO firmware and everything works like a charm. I was wondering, what if I chop the usb cable in half, and add another usb type-A jack? Will the arduino send the midi data to the other connected computer as well? I could just unplug the usb cable from the raspi and connect it somewhere else, but the raspberry pi as well as the arduino will be secured in a case and I don’t want to fiddle with cables after everything is in place.
Thank you! I have also attached a picture of the diagram I have in mind…

It will not work the way you propose because there will be two USB hosts on the bus (each PC is a host). You might need to use two HID Arduinos that communicate between each other, but maybe someone else here has a better idea.

For communicating between Arduinos and/or communicating between an Arduino and Python, see SerialTransfer.h and pySerialTransfer.

There's no need to use Arduino UNO with Raspberry Pi, instead you should use Arduino YUN. Best replacement for Raspberry Pi plus it has Arduino UNO functionality so works best in such cloud based projects.