Usually major patches are followed quickly by an update tweaking ancillary issues to the major ones from the patch coupled with minor adjustments from community feedback on the patch notes and results immediately after release.
Why MLB and Sony released a large, significant patch as V1.09 instead of V1.1 I have no idea, but I'd treat this patch as 1.1 and assume there won't be major changes to the game for quite some time, possibly around or post All-Star break.