
Certified GKH Gardening Expert
This one is interesting! I've never seen this on a pineapple. Typically they prefer decaying wood. This can be adventitious as well. Humidity and higher temperatures can facilitate its growth.
Though it is not directly harmful to your plant, it can be a sign of another infection. If the plant is dying off, then it will be necessary to find out what is causing the initial infection. General fungicides may help for now, but you may need to take samples up to your local extension service for ID of the primary culprit.
https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm
https://www.gardeningknowhow.com/garden-how-to/info/what-is-extension-service.htm