Upgrade coming: American reveals next plane in line for new Flagship Suites

The Fort Worth-based carrier on Monday confirmed it plans to install the suites , which are complete with sliding privacy doors , on its fleet of Boeing 787-8 Dreamliners.

But the new seats they're getting will be the latest-generation Flagship product that American debuted just over a year ago on its larger 787-9 planes.

The 787-8s are slated for a larger cabin refresh, which CNBC's Leslie Josephs was first to report over the weekend.

Expect those planes to get the sleeker new-look interior that the airline has been rolling out across an array of aircraft, which includes brighter blue seats in economy.

These upgrades to American's 787-8s will also give frequent AA flyers another fleet type with the airline's newest, most state-of-the-art premium product up front.

American first introduced the Flagship Suites last year on some of its newly delivered 787-9 Dreamliners.

But it remains a bit of a unicorn seat offering today, as only a small handful of planes sport the new suites.

You'll find the new Flagship product on 11 of those Boeing 787-9s right now , not to mention on Americana's brand-new, single-aisle Airbus A321XLRs.

However, expect to see the suites on many more planes in the future. Later this year, American expects to debut the Flagship Suites on its largest plane, the Boeing 777-300ER, and 20 of those jets are slated for retrofitting in the coming years. Additionally, 47 of its 777-200ERs are also in line for the new cabin and Flagship product.

"We look forward to providing customers with an elevated premium travel experience on our wide-body fleet," an airline spokesperson told TPG.

American's planned on-board upgrades come in the middle of a proverbial arms race, of sorts, among the largest U.S. airlines: The goal is to win big-spending customers over with luxe seats, lounges and other bells and whistles.