yup, wood that has dried 200 years would be great, but almost all production guitars are kiln dried wood that if it's 6 months old you are lucky.
The only difference in the necks really is the inlay, still a maple neck with rosewood fingerboard, although I will admit the rosewood they choose for the 555 boards isn't as nice.
Basically, the only real difference between the 555 and the 7 Series is the inlay and trems. Also, quality Control, this is why some 555's are really good, and others suck. Korean quality control isn't as great, but basswood is basswood, in terms of cutting, Ibanez doesn't care, they have CNC machines that do everything.
One other point of interest, wood doesn't sound better with age, it sounds better with density. Totally dried wood gives a purer tone, but it's not the amount of drying time that creates that better tone, you could have a 5000 year old piece of wood (assuming it hasn't rotted awayLOL) and it could be a totally porous piece of crap, while a 4 month old kiln dried piece is solid, dense, and consistent, and will sound great.
Even PRS and those guys use kiln dried wood, there simply isn't enough time to let wood cure for hundreds of years. Most wood used in guitar manufacturing is about 1 year old.
But basswood will never sound like a denser wood no matter how long it's dried, it's a light wood, and always will be