I'm trying to think this out as I type it, so hopefully it will make a little sense.
I don't think the "Lyric as drug mule" idea likely. Possible, but IMO not likely.
Also, if someone wanted to snatch Lyric in retaliation for DM's testimony against him, it seems there would be easier ways to do this without involving Elizabeth. So unless one of DM's former drug associates just happened to driving by and saw the two girls and spontaneously decided to abduct them, I just don't see this being a retaliation against DM.
This could be a stranger abduction, someone who set a trap at the lake and waited for someone to walk into it. From what Ollipop has described to us, and photographed for us, it seems like the area where the bikes were seen by TG would be well-suited for a random abduction.
But I keep coming back to one theory - that the girls are safely hidden somewhere for whatever purpose, and the entire disappearance was staged. I don't want to go into details of why I think that because my theory involves family members who are still considered victims.
It is so hard to leave the drugs and dysfunctional family dynamics out of the disappearance of Elizabeth and Lyric IMO.