Krashen certainly never posited anything as radical as a recommendation not to produce.

He believes that you can't speed up (or even reorder) language learning by trying to consciously learn to produce on a level that's TOO FAR AHEAD of what you have already subconsciously acquired through previous language exposure (including, especially, enough input, but also enough production practice). He says that you'd just waste some of your time by trying that and that the brain wouldn't pick up the attempted new skills.

Special case: When learning a language without an instructor, it can initially be tricky to get the pronunciation right, and persistent practice of your own, utterly unintelligible pronunciation, can even turn into a fatal setback for successful production ever after. To prevent this, you need to listen (not just read) a lot as you go. But Krashen says that it applies to every aspect of language learning.

Krashen isn't universally accepted, though.

Interesting - that's still learning the stuff subconsciously before outputting though, right?

The example I gave was mine, not necessarily Krashen's.

Krashen distinguishes conscious "learning" and subconscious "acquisition". Both are important. You need a certain level of acquisition before you can successfully proceed to a certain step of learning. But both proceed in a lockstep. There's an optimal proportion between the two to be found; you proceed fastest when you find the right balance between learning and acquisition, says Krashen.

I'm no expert on Krashen so I can't expand this remark into a comprehensive answer.

Krashen's input hypothesis (you can look it up) is purely about acquisition, it doesn't directly postulate anything about learning, so it would be a logical mistake to read it as a prohibition on conscious learning or of production until fluent. But Krashen has also other postulates (e.g., monitor hypothesis) that are about conscious learning and thus way more actionable for self-learners.

I see, thanks for the insight (maybe you could write a partial answer ;)

I'll take a deeper look into it, though from what you mention, I guess people are just hyperfocusing on one aspect and making it their entire method like it's the One Trick Needed to Succeed™️. It happens.

Yes, that's exactly what I meant.