From Jacques More’s How Does Prophecy Operate for an Open Theist:
God’s servants directed and influenced
When the Lord finds a servant of His not heeding His instructions, then just like Jonah he will send outside influence to effect His purpose. In Jonah’s case the Lord sent a storm and a fish to return him to the task given him (Jonah 1:10-17). This is not against Jonah’s will in the sense that He was a servant of God in the first place, but reluctant to do the job he had been given to do, so this is a loving discipline procedure (Hebrews 12:5-11), but as the Lord goes on to persuade him He is also careful to teach him too (Jonah 4:5-11).
Sometimes the Lord has to use someone else, like in the case of king Saul who then was replaced by King David (1 Samuel 13:13-14). Since God is explicit that He “would have established your [Saul’s] kingdom over Israel forever” it was not a previous plan to have David as king. But the job of king still needed doing since the Lord had agreed to that (1 Samuel 8:1-9). So, sometimes other jobs not carried out will also require a replacement, but sometimes jobs are left undone altogether because no one has taken up the job they should have (Ezekiel 22:30). But this latter point is not related to prophecy as when something is declared by the Lord to happen He steps in and raises someone for the task.
It is better to believe and heed the call just as Mary did and believed. The Lord did not impose Himself on her but in sharing with her she believed and agreed (Luke 1:26-38). Joseph her husband to be, then was spoken to by dreams to not only to go on and marry Mary (Matthew 1:18-25), but also to protect Jesus and escape to Egypt (Matthew 2:13-15) and thus fulfil even more prophecy. There was no control or indirect influence here. These were willing servants of the living God and all that was needed to fulfil these prophecies was to provide direct instruction and requests.
Other prophecies were fulfilled by a conscious act that doing the deed would do just that:
After this, Jesus, knowing that all things were now accomplished, that the Scripture might be fulfilled, said, “I thirst!”
This is a good exposition of how prophecy works. God tells us in prophecy what he has decided to happen and that He will make it happen. This is how He knows in advance those things. This thereby shows no suggestion that this forth telling is incompatible with open theism.