Adobe has no current plans for offering FrameMaker natively on Linux.
That's a shame.
Any suggestions then on solutions for migrating from Frame 7.2 on UNIX to an Adobe documentation product on a Linux platform?
Adobe's support for Linux is fairly limited; none of the Creative Suite applications or FrameMaker are available for Linux. You might be able to run the Windows versions under Linux using a Windows emulator, but that is not officially supported by Adobe.