If MAD is over, then that means neither Sharkbuzz and Lavagirl/Barneytubbies or BNFB's idea are being on mad. The good news is, you can still go to MAD fanon wiki to make those episodes reality. So while MAD might end, the fanbase will live on for all of eternity.
If Mrosem6 is reading this, I hope you will stop posting "Barneytubbies" on all the forums, with MAD ending. And that goes to BNFB with "Bill Nye" too. Just go to MAD Fanon Wiki. There is no use trying to get an episode made of a cancelled show.