The paper you link to doesn't use "shard" as a noun, and in fact it doesn't describe a system that has "shards" in the sense that UO and just about everyone else since then has understood that term, i.e. independent partitions of a dataset:
> The reader is referred to [SBK] for a detailed description of the architecture of the SHARD system. Briefly, the main ideas are as follows. The network consists of a collection of nodes, each of which has a copy of the complete database.
(emphasis mine)
Additionally, according to Google Scholar, that paper was only ever cited 21 times. I checked the 16 of those citations for which full-text is available, and not a single one of them used the word "shard" as anything other than a passing reference to the name of the system itself.