The changes coming tomorrow are the servitor stats boosts that were originally a part of the September 5 patch notes. This has been posted many times; please check the official thread (http://boards.lineage2.com/showthread.php?t=245425) on the matter and try to keep discussion and questions about it in that one place.
There are no other Wynn Summoner changes for that maintenance. More changes may come to the class in later updates or patches, but we will have to wait and see.
FYI if any changes were planned based on the player feedback from the past week, it would not have been able to make it into a patch for tomorrow anyways; such things take many weeks at the very least.