Also currently “no” because you can’t boot the Librem 5 from USB stick at all?
However I believe that is theoretically fixable either by extending the boot support or by doing a chained boot. (A chained boot is probably acceptable in the use case where Tails is actually required but only the individual customer can decide.)
So let’s say that Tails were available for ARM and with enough relevant hardware support even to boot on the Librem 5 … for the moment you would be left with installing Tails onto the eMMC drive and that gets away somewhat from what Tails is trying to achieve.
PS I love that people are even asking questions like this !