I've read the terms and conditions for the card and it seems that you're right

"No Miles Expiry

• Skywards Miles are normally valid for a period of three years from the date they were earned as stated in the standard Emirates Skywards Program Rules.
• As a benefit of having the Emirates Skywards Rewards World Elite Mastercard, Skywards Miles belonging to the primary cardmember will not expire as long as they have an open Card Account in Good Standing.
• If the Card Account is closed, Emirates Skywards will communicate an adjusted expiry date for any Miles that should have expired as per the standard Emirates Skywards Program Rules.
• The adjusted expiry date will be two months from the Card Account closure date."

I would do it if I were you. Get the card and get the sign-up bonus, which is not much, to justify the card's annual fee for the first two years.