what happens to xxx@sbcglobal.net email accounts after June 8, 2017

I got an email today from Yahoo about changes in the TOS caused by Verison purchase of Yahoo's "operating business".  What will happen to the three xxx@sbcglobal.net email accounts that we use?  Do we switch pop3 settings to inbound.att.net and outbound.att.net on all of them?  After the acquisition date will we need to use the att.net website exclusively to access those three accounts through the web?  

It would be nice it ATT go its corporate act together and notified what must be many sbcglobal users of necessary changes.