IF the C's don't resign Kyrie, it likely means no AD trade. At that point, they aren't a real player in free agency and would likely be better off building with the J's rather than trading them for a vet star player (I wouldn't pursue Davis since he only has a year left and there's that commitment issue that's looming over a trade for him).
C's would still have Hayward under contract. no sense in trying to trade him since his stock can't get any lower. Horford isn't a trade asset since he's likely to opt out for a longer deal whether it be with the C's or another team (only a concern if Danny makes it clear to Al he's not planning on contending for another couple of years to develop the youth exclusively).
even if Kyrie leaves and we don't get AD, we still have the J's, Hayward (who I am expecting to play much better from the beginning of the season next year), Smart and Horford. Figure them bringing back Morrid and Baynes. They have a developing Williams and probably Semi. figure Danny to get a solid vet PG with the MLE (my preferred option over resigning Rozier). with that roster, no sense in going for a full rebuild. with that in mind, the C's could try to consolidate 2 or all 3 of the firsts they have this year to maybe move up to #7 or #8 if they're lucky. If they see a player they like that's falling to around #10, they may be able to flip 14 and 20 to move up that far but that's about all I see as a reasonable possibility