Well, most of the scenarios cover too narrow a timeframe to have a proper tech tree (I wish I could disable the research slider, actually). The Enterprise scenarios have one, and I actually considered one for both The Dominion War (now Deep Space Nine) and Kazon Unification. When Dominion War was expanded into Deep Space Nine, I found that it was far easier to have techs assigned on the proper turn in order to keep the timeline straight. As for why they aren't in Kazon Unification, I was having trouble coming up with enough and keeping it balanced.
As for the future release schedule:
-1.14 patch sometime in the next week (minor patch)
-1.15 patch possibly sometime this month (very minor patch, possibly no impact but will help modding and possibly speed)
-At this point I hope to make a version of Final Frontier that is mod-friendly, if I can get a SDK programmer
-After that, Version 2.0, including new civs/leaders/scenarios/techs/buildings/units; only 1-2 of these new scenarios will have no tech tree, and only 3 will be based on the Star Trek mod - the other 2 will be based off of the Next War mod.