Israel didn't just woke one day and decided to annex the Golan. It didn't it as part of a war after the Syrians for years targeted the Galilee villages, Kibbutzim and towns, from the Golan. So the Syrians have really lost any moral claim for this territory. If there are peace talks and a peace agreement then the return of the Golan to Syria can be discussed. But The Syrians lost it due to its agrression and they won't get it back by using more aggression.
About 2,000 demonstrators protest 'occupation policy and fascist settlers' in Nazareth (Haaretz)
from the article: IDF fears continued Palestinian infiltration on Syria border