I have opinions on this. Asking for forgiveness in advance because this is gonna be a long one...
In regards to how valid I think the Lawyer Friendly Equines leaks are:
The new intro is probably real depending on the validity of the episode list and given that the episode synopses line up with the intro as well as the footage shown at Hascon this year, they're probably both real.
However, Season 9 being the final season is a maybe, but only truly a rumor until we get official confirmation from The Toy Company. My thoughts of the supposed Lawyer Friendly Equines Movie sequel/G5 prequel movie are the same.
In terms of the "G5 concept art", I'm extremely skeptical. The designs look really detailed which would make it hard to animate in 2D and I don't think The Toy Company would want to invest the time and money into something that costly and time-consuming. This could just as easily be fan art passed off as a leak by an artistically talented troll, but the leaks in the past couple years have been mostly right, so there's that, and again, not 100% sure until official confirmation.
That being said, if the S9 and G5 rumors are true, it starts to bring up thoughts of what I'm gonna do when this show ends as well as whether I'll continue my love of the show through G5. While I don't necessarily want the show to go on forever (Spongebob, Fairly Odd Parents, and The Simpsons are good examples why), I wonder how I will react to the show ending given how much of my life its become a part of. Lawyer Friendly Equines is the only show where I dived this far into the fandom, be it through merch, fan art, forums, etc. And that depth of involvement I've had makes its eventual end kind of scary and brings up a lot of questions. Will I continue to love the show when no new content is being made (in the case of the show at least, not comics or otherwise)? Will I continue to stay in the fandom with no new official content (again, in reference to the show only)? Will I stay if I don't like the 5th Generation that will eventually take its place? Guess I won't truly know until it happens, and the best I can do is hope G4 ends on the best damn note the staff can possibly muster, hope the fandom stays strong after the fact, and hope G5 will follow the standard left by its predecessor and be just as good, if not better.