Arduinos can do "open collector".
Not when they are off they can't. Anyway when they are on the only open collector outputs are the two I2C lines. Changing the lines to an input is not an issue here as the lines that will give trouble are inputs already.
Yes a 7407 is an open collector output but the 7407 chip itself can go into latch up so it is best to use separate transistors or a transistor array.