Yup, new quest, maybe we'll see a huge list of patches, MAYBE early M&S rework, but that is doubtful as they would likely want immediate feedback, so adding such a huge update to the game just before the holidays is a bad idea. A bunch of the devs and mods would be on vacation.
I can't imagine anything else possible, aside from perhaps an announcement to something we don't even know about yet. But probably just the quest and patches. That is "a tad more exciting" than this week's update, after all. Why RS Mobile is a stupid idea