This trade absolutely kills two birds with one stone. We save $3,800,000 (depending on if other players are coming back from Detroit) and we get a starting caliber (barely) PF that we desperately need. This probably saves us having to give Rozier away to Utah.
I love Avery but this is simply the collateral damage of signing Hayward and to some extent from having a second max contract tied up with Horford.
This is a positive step to completing the roster but assuming Morris and Horford start at PF/C, we still have Zizic as our backup PF and Mickey as our backup C.
I see the starters as Thomas, Hayward, Crowder, Morris, Horford with Smart, Brown, Tatum, Zizic, and for now Mickey as the positional backups. Rozier may beat out Brown or Tatum in the rotation, at least to start.