Coming on the heels of the delayed and vague Time of Your Life arc, this stand alone issue is primarily light fluff with an underlying deeper meaning. Kind of. If you stretch the whole 'you can't change the future' tidbit tossed in.
While we had to cope with Buffy traveling into the future with ToYL, in After These Messages we find Buffy either in the past or dreaming herself in the past. Is it real? Does it matter? I suppose that it matters very much to Buffy in that she has an inescapable destiny, and going back to her first year at Sunnydale (post the pack of hyenas eating Principal Flutie because we've got Principal Snyder) only serves to reaffirm what she already knows about herself: Being the slayer supersedes everything. Family, friends, the love of her life, all of those things teeter precariously on The Chosen fulcrum. Of course After These Messages doesn't quite address these issues because it is a single issue, but it does touch upon them lightly.
I'm really looking forward to the next five issue arc starting with the Jane Espensen penned issue #21, Harmonic Divergence out on January 7. The series seems to need a shot in the arm, and if anyone can deliver, Jane can!