You shouldn't stop reading at the end of the "either" branch, but continue to do so with the "or" branch
Depending on a future microcode update's nature (if possible at all...), it might get applied by the installed OS as well, without changing the BIOS version. M$ did so (or in case of eg. VMs tried to do so a while ago) already, but as I wrote: It depends...
Of course, all this shouldn't stop you from hoping and keeping your fingers crossed. But I, personally, wouldn't hold my breath.
At least, you shouldn't hope for an official statement from Fujitsu in this forum. Instead, open a ticket with them.