There are no limits on sharing, transferring or purchasing points for Select Executive members, who also receive an upgrade credit to the next class of service for every 3,000 points earned on purchased fares. (pointsaway.com)
Systemwide upgrades provide an «upgrade to the next class of service.» (thepointsguy.com)
However, once American Airlines launches its premium economy class of service, the «next class of service» after economy would be premium economy — not business class. (thepointsguy.com)