So not to keep derailing the other thread, I see Blackberry is aware of the issue with no fix in place. It was recommended on Crackberry to delete the account, reboot the phone (Vol. Up/Down), and then add back the email account. Kind of a long drastic measure since I have eight email accounts in my phone. Still wondering about doing the security wipe (which will clear all) and then restoring everything but email accounts but again that's just nuts.
KB34279-Unable to clear the recent contact suggestions that are displayed when composing an email on the BlackBerry 10 smartphone