We have had a few resurrections in the cosmere, but none that would apply to Gavilar.
Jasnah
Was actually a fake out, as she jumped to Shadesmar. She didn't leave a body behind. Gavilar's body/death was seen by many people, including relatives (Jasnah, Navani) who recognized him.
Szeth
Szeth was revived by Nale almost immediately after his "death" using a special fabrial. We don't see anything of the sort happening.
Kelsier
Kelsier was able to survive because he was infused with Preservation's Investiture in the Well of Ascension. Had that not happened, he would have gone Beyond after a relatively short time. For something similar to have happened to Gavilar, someone would have needed to have found him in the Cognitive Realm and gotten him to a large source of Investiture quickly. No Shardpools were nearby, and his assassination was unplanned.
Returned
Returned are directly revived by Endowment blessing them with a divine Breath. We have no indication that any of the Rosharan Shards are doing something similar. Returned also wake up relatively quickly after their death, which Gavilar did not do.