I suppose it is; still this episode accomplishes quite a bit:
-It reintroduces Ali (obviously)
-It introduces Red (who may or may not be seen again in certain episodes )
-It reintroduces the Old One (who never had much of a character in the first place)
-Most importantly, it does NOT have Ali leave the valley at the end, even though this is a possibility. It's also possible that this episode was created in order to make good on the promise at the end of the fourth movie, which has now been fulfilled. Still, if this episode was going to be the ONLY one with Ali in it, they probably woulden't have introduced a friend of her's (Red); why go to the trouble of making a whole character if he's only going to be use in a single tv episode? Was it just me, or does Red remind one of Shorty?
-Finally, we now have, by the end of this episode, Littlefoot, Cera, Spike, Ducky, Petrie, Chomper, Ruby, Ali, and Red in the valley together. That's more than we've ever had at once. Of course, it is possible that Ali won't appear again (I hope that this isn't the case; her herd is or was migratory, you know), and probable that she won't be back for at least a few episodes even if she is back.
I was surprised by the lack of Littlefoot's grandparents, or the appearance of any of the parents. Still, this was a good episode, but not the overwhelming spectacle that we had been secretly anticipating all these years.
EDIT: This episode marks the third important non-main character (not including the parents/grandparents) to return from the movies; Chomper returned in the first episode and became a main character, Tria probably came in the second episode (with Tricia), and now Ali is back, but for how long, and how often will she be seen? Was it only for this episode? Will Red also return?; it doesn't matter too much if he does, in my opinion.