TeraByte Unlimited

When I booted into the recovery environment there was no Terabyte option to choose. I suspect the Anniversary update had just replaced the old environment with a completely new version ignoring any additional items in there.

Can I assume that I should just re-install TBwinRE from the Windows start menu item?

Yes, just run it again. It will update to the new version and recreate the build.

I should add to make sure you're using the current version of TBWinPE/RE Builder or the TBWinRE.cmd script before running it. If using older versions it may not update to the new WinRE correctly.