Yeah, Captain Shaw does has a point. Simply petitioning Hasbro and Katrina Hadley is not going to help.

The proper way to 'save' Equestria Girls, is to just simply draw fanart of the characters themselves and post it to your online art page. Or write fanfiction and post it to FIMFiction. Or make SFM/animated videos of them.
Or just go to Fifteen AI/Uberduck and do audio drama of the characters. Or read "The End Of Past Memories" & "A Tale Of Two Sunsets" by Pauly Sentry and EmeraldBlast63 if you're craving for an EQG finale. Or binge watch existing episodes over & over again. Or dance to the songs in EQG. Or make your own cover of an EQG song, whether instrumental or by voice (you can even do it with a choir for fun). Or cosplay as any of the characters.

And EQG will not enter the public domain until maybe the Federation Charter of 2161 is signed. (Hopefully, the Twelfth Guarantee doesn't take over EQG's copyright)