I don't see any connection between K-3 not being approved and I-130 being approved. Ok, they find K-3 and toss it in a bin. Why would they then go and approve I-130? I couldn't find anything in the manual saying "If K-3 is admin closed, go adjudicate I-130". They can close K-3 and leave I-130 alone until the time comes to adjudicate it. USCIS operates according to manual, so if it works, it has to be documented somewhere.
Occasionally I-130s get approved in under 3 months without expedite, K-3 and other things done about it. Some people get lucky. I don't see a link between filing K-3 and getting faster approval.
Either way, I understand that many file K-3 out of desperation. Until somebody can show solid proof of it helping I-130 approval on consistent basis, I'll be advising not to count on it and prepare for case to be adjudicated according to current processing times.