Because it introduces new items, there should be a client update as well. The only way there wouldn't be a client update is if VR is working on a system to dynamically update files on app load.
It is possible that they are working towards that. That could probably explain why the Samhain update was bugged - if they were testing that functionality, there may have been unresolvable issues, which might be why the client update was late.
On the other hand, it's also entirely possible that VR simply forgot to submit the client update to the stores for review before Samhain, and they aren't working on any new methods of updating files.
With no other info than what I have seen, my personal guess is that yes, there will be a client update.
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