Voyager was getting it's ass kicked. The Prime Directive still applied.
TORRES: Apparently thousands of them were built as service modules, but the race who created them, these Builders, were killed off decades ago in a war.
JANEWAY: Leaving the automated units to fend for themselves.
TORRES: Now they're wearing out, breaking down. They've learnt to make repairs to themselves, some pretty complex, but the construction of a power module, the device that sustains them, is beyond their grasp. It's an incredible challenge, Captain, but with enough time to study their systems, I might be able to do it.
JANEWAY: I don't doubt your abilities, B'Elanna, but helping them reproduce is a clear violation of the Prime Directive.
TORRES: They've expressed a desire to procreate. That's basic to any life form.
JANEWAY: I'm not saying they don't have the same rights as any organic species. That's not the issue here.
TORRES: Are you sure? Suppose they were organic but they had become sterile, and we had a treatment that would enable them to start reproducing again. Would you withhold that treatment?
JANEWAY: Maybe. I'd have to know more about the circumstances. But we're not talking about treating a disorder here, are we?
TORRES: What's the difference?
Warp capable threshold... Tick!
From Blink of an Eye.
PARIS: Well, we've got to let them know we're not doing it on purpose.
TUVOK: Inadvisable. The Prime Directive still applies. This transmission was made with primitive radio technology. They are not a warp-capable civilisation.
PARIS: To hell with the Prime Directive. That man deserves an answer.
TORRES: Don't forget the temporal differential. That man has been dead for a long time. EMH: Nearly a century by now.
The warp threshold doesn't rescind the Prime Directive, it just loosens it a little, like with the barriers to drinking booze and a persons age all around the world.