That I don't know. The part I put in quotes came straight from the warrant so the Affiant believed that BB had engaged in message transactions constituting evidence in the murder investigation and possibly other offenses via Facebook.
I think there are a number of people here who have and even continue to believe what you believe and have and do mention WH and BB/WH. So it isn't as if no one is speaking about it.
My own personal take on it is if MPD were told or discovered that BB had or was having a relationship with anyone they would have hung him out to dry publicly along with the other person just like they did with CW if they thought BB was involved in some way with Missy's murder in order to ramp pressure on him especially via his kids finding out, Missy's family, Missy's friends, etc. In cases like these spouses are the default suspect so it surprises me that if they had any such information that they didn't use it to their advantage.
As for how they would communicate without being obvious it would be almost impossible once someone is looking to find such communications. If you do some research you can find various techniques that cheaters use - up to highly sophisticated opsec including codes, voice-mail drop only phone numbers, skype (and similar) over the web via private browser from their phone, etc. - and all of those can be detected, even if the communication contents themselves cannot be recovered. The only reasonably safe opsec cheaters can use is to only communicate face to face and make sure that no one - not a single person (including waitresses/waitors/hotel clerks etc.) - ever see them together, which is pretty much impossible as well.
