Does that mean that until quality is researched, you only get normal quality items? Otherwise it sounds like stacks would break.
The start of quality is slightly unclear in the article.
"Not all of the quality tiers will be available from the beginning" sounds like some quality tiers are available (but invisible) from the beginning of the game. Even though the next phrase suggests that's the beginning of quality research.
You cant normally (without usage of cheats or editor) get the quality modules before activating the research, but yes, theoretically if you cheated the quality modules in before the technology would be researched, the modules wouldn't really do anything useful, as they couldn't go higher then normal quality.
Here, by the beginning, we mean the research of the first tier of quality modules.