Mature Succulent is a popular term (老桩/ 老椿 in Chinese) to describe when a succulent is older than 1 year usually the succulent has grown tall but tough and strong . Sometimes they are more likely to have lotsa pups and survive any harsh conditions. Look at their trunks
Sample of mature ladies:
Another sample
In comparison this is still growing plant. You can see that her stem is still soft and chubby. Young stem doesn't mean they won't grow pups however they might be slightly more fragile than the mature plant.
You can find the mature succulents from my shop