We can only assume they were Verizon phones because of what DB & JI's attorneys stated, but we don't know. We also don't know if DB & JI had different cell phone carriers.
I researched the Verizon phones a while back after the attorneys came out and said "Verizon", and I was a Verizon customer up until 2009. My phone did not require a sim card, and the contact list was stored in the internal memory. I had to manually input all of my contacts into my AT&T phone when I switched, which was a pain. I remember putting in all of the important numbers, and even the other day I powered on the Verizon phone to find a number of an old contractor I used for heating and cooling.
IF there was a call made to MW's phone or an attempted call, it sure would be like looking at the odds of winning the lottery. Let's assume someone was attempting to dial the first three numbers (the prefix) because it was a common one. There are 10,000 different combinations for this to have been a wrong number.
(If you want to work a real brain teaser today because you are bored, calculate that with a 7 digit number



-xxxx and the first number cannot contain a 1 or 0. If that isn't enough, add three more digits to it for an area code, and remember the first number of it also cannot be a 1 or 0)
I've seen speculation about people saying this was a wrong number.
Take into consideration DB claims she didnt use the phone that night, and if we go by their attorneys accounts, only one phone call attempt was made from this phone at almost midnight, over three hours before they claim any other activity was said to have been made on that very same phone. For someone to attempt to dial only one telephone number and for it to be a "wrong number" seems to be that I could pick 5 numbers in the lottery this week.
IMO, there is a mystery here that still hasnt been solved.
Still, if I take the source the information coming from as credible (from JI & DBs attorneys), if a call attempt was made at almost midnight, where did these phones ping at for over three hours before other attempted activity occured on these phones after 3am? If someone took Lisa at 11:xxpm and the phones then tried to dial a number, certainly the pings would have moved away from the residence or triangulation pinging would have showed movement of the phone(s).
Did the phones continually move around between 11:57pm ad 3:30am and stop pinging? Did they stop pinging inbetween? As I previously stated, so many unanswered questions.