If they do not absorb their eggs, they may try to spawn. The odds of their success is minimal. Trout require very clean pea size or so gravel with current, high water quality and high DO levels to successfully spawn. If some miracle did occur and they did successfully spawn, most of the eggs would probably die because of a lack of those conditions. If another miracle occurred and the eggs did hatch, as you mentioned, the predators in your pond would most likely clean them up quickly. Many trout streams that have great trout populations would not have them if not for fingerling stocking. The YOY and 2nd year trout make great food for larger trout and other predators. Few streams have habitat needed to rear young trout but do have habitat for bigger trout. Brook trout are the only trout I am aware to successfully spawn in ponds and even that is a rare pond with unusual circumstances.