Specialists (and regular steps too, in fact) need to be suppressed when added, otherwise there's the following very simple "gamey" exploit.
Suppose you have a really big map like Case Blue, or Kuibyshev. Suppose you also have a bunch of valuable armor or engineer specialists on one end of the map. You could then use "reorg" to put the specialists in the force pool, and immediately on the next turn they would be available to use on the other end of the map. Making them suppressed simulates the time needed to integrate the specialist unit into you existing formation, but also importantly puts a one turn break on the exploit described before.
We did discuss the following variation during the beta test, but it got scrapped because of release date pressures: when adding specialist and regular steps during first turn only, they are not suppressed. This would be like the "deployment" mechanic found in some other games. I'm fine with it generally. The only problem is that is possibly gives an even grater advantage to the first player. This could be a problem for multiplayer games, where P1 is already at an advantage simply because it's a IGOUGO game if nothing else.
Unity of Command Lead Developer