Usually if there are participation requirements it is mentioned earlier in the document, not in the reallocation section. It could mean that for the quota to be reallocated there must be four competing athletes, rather than the original quota needing at least four competing athletes.
If they do mean the original quota that pretty much voids the Oceania qualifier, unless there's some coordination and they can get 1 or 2 weight classes. It can also affected some of the other continents in the women's -67kg and +67kg, for example, the Asian women's -67kg qualifier only had 3 athletes.
Maybe the intent is they didn't want athletes getting a free quota for just showing up like Jordan and Tonga in women's -67kg and Australia in men's -58kg, but then they should make a rule saying that the qualifying athlete must defeat at least one opponent (also allow a three person bracket be round robin for the continents with two quotas)