This is not a problem indemic to the "new" tickets. It's a problem with any type of card that has a magnetic strip - WDW tickets, hotel room keys, ATM cards, credit cards, etc.
Magnetic fields can demagnetize these strips. Magnetic fields are created by any electrical device, from a lamp to a cell phone to a TV. And guess what - batteries have magnetic fields, too, so turning off your cell phone is not always a solution, because the phones battery can still demagnetize a strip.
The problem seems more common at WDW, but only because WDW issues hundreds of thousands of park passes, room keys, and other tickets every week, and people naturally seem to put them all together in a pile and store them in lanyards, pockets, and fanny packs.
There are several precaustions you can take to reduce the possibility of demagnetizing your tickets and room keys:
1) Store cards in a remote location from any electrical device (phone, camera, radio, etc.) Keep at least several inches between the cards and the electrical devices.
2) If you have multiple cards, be careful how you stack them. Don't let the magnetic strips come into direct contact with each other - one strip rubbing against another strip in a pocket or lanyard pouch can demagnetize both, just like rubbing a magnet against a cassette tape.
3) Keep cards away from heat and moisture. This is especially difficult in a theme park environment, but it can be done. Heat causes static electricicty, and static is the enemy of all forms of magnetic data storage, including the strips on WDW cards. Moisture can cause the paper coating of the Tyvec tickets to expand and contract slightly, stretching the magnetic strip just enough to crinkle it.
4) Keep cards in some kind of a container, rather than just in your pocket. Neck lanyards are popular, as are waist packs - but don't just throw the cards into a large open pocket of a waist pack, be sure to use a waist pack that has credit card pockets.