Either I missed this bit in the FAQ when writing my previous post, or it has been updated since writing that post with this statement:
I'm not sure how to interpret this. On the one hand, you could interpret this as saying that the graphics card just fires off new frames when the monitor is ready for them, since it knows how to do so. Presumably the monitor would just hold the frame for as long as it needs to with this system.
On the other hand you could say, especially with that last sentence, that the monitor is being told when it receives a frame that it needs to hold it for a time predicted by the graphics card (which the graphics card knows is an acceptable time since it has determined the monitor's minimum and maximum refresh rates), rather than the monitor constantly asking "do I need to keep holding this frame" and the graphics card replying with its answer.
Again, If I had to guess the method without frame time prediction seems more likely, but there might be some complex reason for requiring frame time prediction. Just a simple yes or no answer to "does freesync utilise a method for predicting how long a frame will take to render, or how long it will need to stay on the monitor" would be great