Wow , That why this forum is good. I did some checking and found out Verizon does support the BB10 OS on the classic phone but I cannot find it's Verizon model number. Not sure it's called 8300
Verizon does offer a web site for support and it does detail the BB10 upgrade along with a lot of other info. Really good stuff.
https://www.verizonwireless.com/support/classic/