I'm not sure whether the Gene the controles whether the plant is auto flowering is Dominant or recessive.
Assuming that the Gene is DOMINANT (i.e. only one of the gene pair needs to be autoflowering) there would be around 8/9 chance that the offspring would be Autoflowering.
If the gene is RECESSIVE (ie. both genes in the pair need to be autoflowering) the offspring would DEFINATELY be autoflowering (as neither plant would have any 'Non-autoflowering' genes to pass on).
So yeah, the offspring would more than likely be autoflowering(or at least most of them).
This might be over simplified, but going on what I know about genes in general, thats my hypothesis.