Seems like Company News Timeline, the solution provided by Microsoft, includes far more than the features it offers. It also has the full Account, Opportunity and other entities.

Where we ran into issues is that it over-rode the settings we had for relationships between accounts and opportunities, and parent accounts to accounts.  It changed them from configurable cascading to parental. We didn't notice for a few weeks but had mysterious issues that we couldn't figure out. Traced it back to this.

Microsoft has been notified but as a PSA to everyone else, use caution when installing.  Doublecheck everything you had set up or customized prior to installing because you may lose your customizations.