I don't think the mozzies will lose their grandfathered F16 status, atleast not in the short term, unless they make a big change to their class rules.

The F16's may get a run for their money at the moment by the top mozzies, but mozzies are relatively one design now and so their performance will stay close to what it is currently (it may pick up a bit with some more kite development). The F16 concept and the current designs still have a fair bit of development and maturing to go yet, it's performance will improve over time.