No. From the outset, the producers said they wouldn't want that to happen in the first season of the show, since they wanted to give "Joey" a chance to stand on his own.
But I think it's more of so as not to remind the audience how lousy Joey is when he's all alone. You'll miss his Friends even more if you get a small taste of them again!
So if I remember right, Chandler was mentioned in the pilot, then Rachel was alluded to in the first part of last week's season finale (and not even mentioned by name!), but that's it.
After disliking then liking the show, the last few episodes put me back into the dislike column. One episode completely recycled a joke from season two of FRIENDS -actually copying the dialogue word for word! And even the show's writers seem to have forgotten about what's going on in the show-within-the-show: Colby Donaldson's character was killed off, then brought back as a ghost... and now, in the finale, is suddenly alive again... and in danger of dying. Huh?
If the writers themselves don't care about the show's continuity... how can they expect the audience to?
Sloppy work all around. Season One's done, so that "stand on his own" premise is done! Now bring back Rachel.. or Phoebe... or Monica & Chandler... or Ross... or even Marcel the Monkey...