In theory, 19 twinking could come back in a future expansion...if it does, you have two options today.
1. Don't make a 19 twink now because it doesn't do much. If twinking comes back, make a 19 then.
2. Make a 19 now just in case. Theres a chance that some gear is obtainable now that will be unobtainable in the future. But you never know, and its a lot of work to collect a bunch of items on the *chance* that 19 twinking comes back and the *chance* that the items become unobtainable and are good.
So basically, I'd say don't make a new 19. If you already have one, I'd leave it there for the future just in case.