The ADB BBS had
a submission topic running for Neo-Tholian design ideas; so far, there hasn't been any unveiling of its results, but it seemed that the intent was for the Neos to be a part of the second wave.
But, there's probably no point speculating overly much, since it seems that upcoming books seem to be moving away from being set to match
FC/
Starmada releases the way the first book had been.
For anyone who isn't aware, the ship list in
A Call to Arms: Star Fleet is the same one seen in the first four
Federation Commander modules (
Klingon Border,
Klingon Attack,
Romulan Border and
Romulan Attack) and the first two Star Fleet
Starmada books (
Klingon Armada and
Romulan Armada).
This is where the ship compositions for the first twelve Squadron Boxes came from; since each of those was originally offered in the older Starline 2400 range, each keyed to a given
FC release (over which the
Starmada books were overlaid).
This may be another thing to watch for if book 2 moves away from this; some of the Starline 2500 versions of certain Squadron Boxes might have to wait until the missing empires in a given box are gotten around to.
As a further example, the
FC modules
Distant Kingdoms and
Hydran Attack introduced the Lyrans/LDR, Hydrans and WYNs to that game system; both modules were consolidated in
Starmada terms in
Distant Armada, while a set of six Squadron Boxes exist in Starline 2400, three per
FC module, to support these releases. However, if that set of ships are broken up for
ACtA:SF purposes, one or more of the Starline 2500-edition Squadron Boxes may not be offerable right away, since they would include ships from empires that happen to miss the cut.
In the long run, once more books are out, it may not matter so much; but it may well be a factor in the time we have until we get there.