“Irrealis is real“, but what are the predictions?

Semantic typology is based on semantic comparative concepts (or comparison meanings, as I have come to call them), and these concepts usually have labels that come from a particular language. Thus, the Concepticon, a systematic list of 3971 comparison meanings for word comparison, uses English labels for its comparative concepts. In grammar, we often use terms derived from descriptions of European languages (e.g. genitive, perfective, 2nd person), but increasingly our general terms come from...