There is a new blog post from Microsoft: “Unexpected error from external database driver (1). (Microsoft JET Database Engine)” after applying October security updates. But I cannot follow the argumentation ...

I do not have any problem with the mentioned workarounds, but neither

• SQL Server Management Studio 17.3
• nor SQL Server Data Tools (VS 2015)

are using the workarounds and are facing the same problems.
sp_addlinkedserver docu still lists JetT.OLEDB.4.0 for Excel.

So in my opinion this update was not well planned! Even if you can hold back the updates for 2 or 3 more weeks (and then use the new patch), you should plan to eliminate the usage of Jet.OLEDB.4.0 in your environment.