Air cycles out of the system without any bleeding required. I know this from experience. I don't need to know how it does it or the hydraulic fluid theory to know that it does. I don't know how my computer puts these letters on this thread but I know that it does put a D on the screen when I hit the letter on the keyboard and it has no wires so it transmits wireless. I don't need to know how that works either, it just does. One does not need to know theorem mechanics about tractors to know that if I pull back on the FEL lever, I expect the FEL to raise. I don't need to know how the pump is powered, fed, pressure delivered etc., just that it will work just like the air being removed from the new cylinder.
Fluid level being maintained with correct type in your tractor is about all you need to know as long as it is working which 99.99% of the time it will continue to work as long as all fluids are maintained and serviced as recommended.