Seems like curious terminology from NV. In estabilished use, SMT means executing instructions from several cpu threads concurrently in the OOO CPU's execution units so they are not starved from work, whereas timeslicing conventionally means context switching between threads/processes, alternating temporally.

In operating systems timeslicing means giving a quantum of execution time to each process, and context switching between processes. Not normally a term used in computer architecture but possibly the characterisation would fit a barrer processor rather than SMT.