It looks like the proposal is exactly that: increase orders by governments / the military and some regulation that prioritizes eu orders over others.

I only know about the german manufacturers and they would be ready to increase their production but did not receive the orders yet.

I was listening to a podcast the other day (could have been "Rachman review", which is typically very good) and the interviewee said that yes, there might be interest in this, but companies want to see long-term orders before committing. There's currently no capacity, so they have to build it on their side, but they don't want to do it if they think the orders are going to dry in a few months / years.

A few orders aren't enough for companies to invest in more capacity. They need assurances that their products will be bought for at least 10 years or so to even recoup the initial investment. Weapons factories are expensive and thus risky to build, but government guarantees can eliminate that risk.