I think the entire phone system could merge back into one company, and no one important will blink an eye. It's a different world. We now have various cellular companies offering phone service, not to mention hundreds (thousands?) of various sized VOIP internet companies.
For instance, in my household alone I use a cell phone and MagicJack each tied to a Google Voice number. We use Spectrum/TWC here. Landline company mergers won't even affect many of us.
While mergers could be a big problem for communities that are far from being served by cable or good cell service, it could be a nice incentive to start local internet co-ops.