Yeah, those labels are necessary for commercial sale/export. My understanding is it is only needed for new items. In any case, there's three possibilities for these items:
1. Manufactured before the collapse, but didn't get allocated to a particular organization (NVA, MdI, etc.).
2. Manufactured soon after the collapse. Some factories continued production for a short period simply to keep people showing up to work. IIRC the West German government kicked in some money for this.
3. Manufactured significantly after the collapse. Surplus materials were used for the surplus market.
I don't think case #3 applies here because who in their right mind would spend money to produce one of the least desirable types of surplus? Winter stuff is not easy to get rid of compared to summer. #2 is possible, but I think #1 is the most likely.
Which is to say these uniforms are most likely legitimate DDR production for its forces, but were never allocated and therefore technically not an issued item. That's splitting hairs IMHO as these things are in every way identical to the stuff that DDR soldiers were wearing. However, hair splitting is a part of collecting