I guess it doesn't let me edit my original post, I wanted to make this more clear.
Line A: dumbphone, no data plan, has an upgrade available
Line B: smartphone, unlimited data, no upgrade available
The plan the phones are on is Nationwide Talk Share 700.
The rep tells me that I can go ahead and do this:
1. On the website, order the phone I want with Line A's upgrade (the dumbphone).
2. Once I get it, call Verizon and activate the new smartphone on Line A. (my question is, won't I get saddled with paying for a data plan?)
3. Now, switch Line A's phone to Line B.
4. Reactivate the dumbphone to Line A.
I see many things in this forum saying it can't be done, and many people arguing you can. Even the reps at Verizon say yes, it will work. However, I am reluctant to try it due to everything I have read here.