I scanned over the ldd output of the repo, and there were about 20 extensions that needed libxcb before the pango update.
In the case of those mentioned, pango, thunderbird and lxterminal were not linked to libxcb before their recent updates, but now all three now have files that are linked to libxcb. Since pango now depends on libxcb, that will take care of the libxcb dependency that has snuck into any gtk2 apps. I will run another ldd output of the repo later today after updating and see what needs libxcb that does not have it in it's dep tree.