Talgath was going to skip it. Eventually the Legion vanguard would have found and invaded Draenor, as it would have eventually done to every world in the Great Dark.
Finding the draenei was a special mission Kil’jaeden had Talgath engaged in. It wasn’t the divining course by which the greater Burning Crusade was being directed. It was Archimonde’s stated reason for not being uniquely interested in prioritizing their destruction. As far as he was concerned every world in existence was slated to eventually be purged, including any planet the draenei might come to inhabit, so he didn’t really care if they were found sooner or later.
Had the Legion not eventually been stopped, Draenor would have been as doomed as every other planet. It just would have taken longer for the demons to get around to it if Kil’jaeden’s personal agenda against Velen hadn’t drawn his eye there sooner.