I think had it been filmed there would've been a better since of closure for the episode and the Ponds' journey. Plus, made some sense of having Brian introduced in the first place. I think I for one would've liked it better had it been included. I know not everything needs a pat ending but at the same time it's kind of nice to have a last hurrah for the characters we spent time getting to know and like.
Strange Chibnall wrote it, so was it ever intended to be aired or was it just a coda he thought to add?