According to this, yes:Is this definitely confirmed? I have J Saver waitlisted for mid next year from SYD.
South West Pacific
The A380 will return to Melbourne after almost four years on 16 May 2023, while Sydney will receive a second daily A380 from 17 May 2023. The A380 will replace the 777-300ER on SQ237 from Singapore to Melbourne, and the return service SQ228. SIA will also operate the A380 on SQ221 from Singapore to Sydney and the return flight SQ232, instead of the A350-900 medium-haul.
When logging in, I've got a 777 booking that hasn't been changed over to A380 yet.