I don't think Verizon would brick the device. But I think they certainly could find somewhere in their mulitpage "terms and conditions" to justify removing the ESN from their database. At least with a normal 3g phone, they could do that, I'm not sure if the 4g / Sim card will be the same, but I bet it would. Verizon has a track record of only activating devices for whose ESN's are in their system.
Best Buy sold the phone to the O/P. Verizon has no real obligation to allow that phone on their network. If VZW removed it from their database, it wouldn't brick the phone, but make it quite unusable for most purposes.
Heck, I think VZW, in their T&C's has the right to flat-out cancel service. Of course, if they do so, there is no ETF. I've seen reports of VZW doing this in cases of tethering (many years ago).