Unfortunately this is not possible currently. The bot does not respond to its own commands, so you cant create a timed message with this.
From what I understand, there is not much demand for such a feature. So I will wait and see what other streamers think before looking to implement this.
Personally, I feel streaming needs a fair bit of interaction. So raffles running by themselves may not be what most streamers would look for. However, I may be wrong, so happy to hear feedback on this.
Regards,
Experts