I can't see a whole set of new Alien Modules for Traveller5. The aliens have been done to death; we have plenty of copy on them.
But FEE could do both of these:
1. Since the color text doesn't have to change, release PDFs with Traveller5 updates to the Classic Traveller modules, one separate PDF for the Big Five sophonts if there is significant amounts of material, or one PDF bundle for the Big Five.
2. Since FFE owns the originals, perhaps in editable format, edit the updates directly into the CT alien modules and release those as Traveller5 PDFs.
#1 is cheaper
#2 is for those who want it "all together"
And, FFE could release a new alien module to compile together minor sophonts from JTAS issues. Ael Yael, Dandelions, Shriekers, etc.
Editable format? most likely not - except maybe TNE's AOTRv1:H&I.
The CT modules are from the era of layout boards and linotype machines. GDW was ahead of the powercurve, having a linotype machine... but any such originals are likely no longer reliably readable, and the software to read the formats likely absent.
And, unless Marc has purchased the DGP rights, the Vilani write up is nowhere in canon.
CT had 8 Alien volumes (Aslan, K'Kree, Droyne, Solomani, Vargr, Hiver, Zhodani, Daryen), plus another 10-20 in various magazine writeups and adventures (from memory: Newt, Virush, Ael Yael, Dolphin, Sword Worlder, grugach Kar, Jagd-il-Jigd, Cymbeline Chips (A13), Shriekers (A10))... several more got little more than a paragraph or two (Dandies, Eiboken).
MT only rehashed 3 of the 8 (Solomani, Vargr, Aslan), added the Vilani in major level, and added another 5-10 magazine article aliens (of which I remember only the Jonkereen); the rehashes were third party, as were the vilani, and some of the magazine aliens.
TNE only had 5 treatments to my knowledge, 1 new significant (Ithklur), 1 rehashed major work (hiver), and capsule conversions for several prior ones (in Reg. SB), and a 3rd party significant minor write up in glorious detail (Vegan) in Traveller Chronicle.
T4 had the Aliens Archive - 20 some, of which 5 or so were rehash, and all of which were only magazine article level of quality.
T20 had capsules for the majors from CT, and added capsules for 5 of the lesser CT aliens, plus added the Ursa. Stats incompatible, tho.
GT has dozens of aliens - but magazine level detail for the majors, and incompatible stats and methods. Most are capsule level. But they are SJG's, not FFE's.
Only CT, MT, and TNE had good detail levels.
MGT, like GT, isn't Marc's. And the alien modules are well done, tho' not well done
as canon.
So, really, the aliens haven't been done to death. Most of the 40 or so known Alien Races have only a page or three.