At the risk of 1) being wrong....and 2) starting another DIS holy war.......
Are MYW tickets issued in with the owner's name? IF so, and IF the ticket is issued in your name......and IF you return to WDW and use "your" ticket, I suspect the following MAY happen:
* You go up the gate and stick "your" ticket in the machine and your fingers in the bioscan.
* The bioscan will not allow you entry.
* The CM working the turnstile will ask you to try again, and it will fail again.
* The CM will rub your ticket on their clothing (why DO they do that?) and try a 3rd time....which will fail....again.
* They will then ask to see your ID, which you will show them, which will match the name on your ticket....and they will let you in.
* This scene will repeat itself each time you attempt to enter a park, unless you have your bioscan redone....which I BELIEVE you can request be done.
I'm sure (and I hope) someone more knowledgeable will be along to confirm or refute the above scenario.....and no doubt, more than a few will remind you about the explicit nontransferabilty of Disney ticket media.
Good Luck. And if I'm wrong, just think what a nice early Christmas gift you have just given your nephew!
Stan