Oh, and a little vent screw to burp the air that gets squeezed out of the fork oil (I guess)..
If this is really true, it is a very important improvment : it means that the fork will be softer in compression as the air chamber will not be closed anymore. When I changed the OEM springs for Wilbers progressive springs, I also increased the air chamber size, by removing some oil, and this has softened the fork in compression.
Air is compressible, when oil is not and if the air chamber is no more closed, it means that oil and air are no more used to manage the compression behaviour. Oil is only used for damping, then.