With timechart everything works fine, it plots using dataset.field or even with "field" after rename. But predict doesn't seem to be taking any option as input. Only way predict works here is if I use direct value of the field.
| tstats summariesonly=true count FROM datamodel="modelname.dataset" where dataset.field="xyz" by dataset.field, _time span=1h prestats=t
| rename dataset.field as field
| timechart span=1h count by field usenull=f useother=f
| predict field
--- If this reply helps you, an upvote would be appreciated.