According to what I know about it, that's a bonus to all weapons, hull repair, and shield repair.
At the least you lose out of the power level bonus it had before.
Though I haven't copied my joined trill over yet to see it personally...
If the bonus to the efficiency still remains you're still loosing out slightly on the 'other' types of bonuses the old t1 skills had as they affected 'all' skills higher in the tiers as opposed to just a specific subset.
+3.3 Starship Energy Weapons > +3.3 Starship Weapons Training
+3.3 Starship Projectile Weapons >+3.3 Starship Weapons Training
+3.3 Starship Warp Core Training > Nothing
+3.3 Starship Engineering Training > +3.3 Starship Hull Repair
+6.7 Starship Operations Training > +3.3 Starship Shield Emitters
Now, those are all bonuses that aren't in any other trait, that I'm aware, but it still feels like a nerf. I rolled Joined Trill to play a scientist, not a healer.
So the efficiency is a net loss, and the eng and ops are 'different'. With the ops being a 'smaller' value compared to its former one.
The difference being... Going from a bonus to all aspects of engineering/science, to buffing healing.
Ignoring the possibility of the same numbers providing a larger bonus, it is still a loss of versatility in the trait.