I still don't understand how you could do prequel factions in Armada. It doesn't make sense.
You can do them as continuations of the current factions. They don't fit. The Republic are the good guys for 2.5 movies, then suddenly are the bad guys leading to the Empire. The ships are more like the Empire, but most of their characters are more like the Rebellion. However some of their characters are straight up Empire as they continued on to serve that faction. So the Republic sort of fits into both factions (which makes sense as they are the basis for both factions). The Seperatist ships don't fit either faction, and their characters are the bad guys for all 3 movies. Giving triangles to the Republic seems odd, but so does giving Obi Wan to the Empire. Giving the Seperatists to the Empire makes no sense, and giving Grevious and Dooku to the Rebellion feels a little off. Keep in mind that Palpatine was leading both factions.
As new factions, you'd need a HUGE injection of new pieces all at the same time. Even if you gave each faction 1 large, 1 medium, 2 small, a flotilla, and a squad pack of 4 squads....you have a underpowered faction that can't compete. You'd have half the ships, less than half the squadron type with an even smaller set of squadron choices, and half the commanders. Your options would be severely limited and this would make the factions easier to counter. Beyond that, to intro 2 factions like this would mean 2 large, 2 medium, 4 small, 2 flotilla, and 2 squad packs released in 1 giant wave that would be the equivalent of waves 1, 2, and 3 released at the same time. FFG can't give us regular releases, yet they are going to do a super massive wave for new factions? Anything smaller than that size of release would make the factions completely unplayable. If they try a 3 wave release over a year or year and a half, no one would buy in to get a junk faction that isn't playable (imagine just playing Imp wave 1 in today's meta).
Even if they did a super massive wave, they'd have to follow it up with a couple more waves to really get them up to par. So then you are looking at 2 years of new faction only releases to get them up to speed. To continue to support the existing factions with something to keep them active and interested, you'd need waves larger than anything we've seen since wave 1.
To do ANY of that, they'd need to put Armada in the primary production slot, which doesn't appear to have a chance of happening. X-wing is a bigger seller for them, it just launched 2.0 and new factions. Legion is still pumping out new stuff like crazy. You think they are going to sidetrack any of that to put massive support behind Armada?
That's just the logistical problems. Now lets address the customer side of things.
The new factions will have new upgrades...but existing faction fans won't want to buy them, and this will likely drive some customers out. Buying into 1 faction and trading/buying upgrades you need is one thing. Buying into 2 factions to get everything is acceptable to some. Having to buy 4 factions or trade/buy for upgrades from 3 factions gets a little overwhelming.
If they ignore existing factions for very long, players will just quit.
New factions likely won't attract new players. It'll only eat into their existing player base as some people move to the new factions. This just means more SKUs to keep in stock, more SKUs to develop, but the same number of players. That's a losing business proposition. You MIGHT pull some of the lapsed players back with this sort of move (but you could do this in several other ways also), but for how long if you don't keep steady support for all factions not only with releases but also with some customer interaction in the form of articles, news, etc.
FFG can't support their current armada factions or player base, yet will somehow successfully launch entire new factions to a dying player base just doesn't seem like a reasonable expectation.
Doing a Armada 2.0 and dropping the Empire/Rebellion support all together to do new prequel factions would likely kill the game before you could even get comparable factions to what we have released. The number of players attracted by this maneuver would likely be far less than those that would call it quits.
While the original trilogy is pretty much tapped out, they could draw more from the old extended universe (already have for some games). They could also move into the new trilogy factions as extensions of the current factions. The cartoons, comics, movies, and new live action show will provide them with new material that could/would fit into the current and new trilogy factions. (Resistance has introduced new characters, the movies have introduced new characters and a few new ships, the comics have introduced several new ships, there is another movie on the way which is likely to have a larger fleet engagement with more new capital ships, and Mandalorian is bound to give us new characters and potentially new ships)
While I'm not opposed to the prequel trilogy making a showing in Armada, it just has WAY too many obstacles, risks, and potential to hurt the game in the long run from a business perspective. Continuing into the current trickle of new content seems like a much easier path logistically speaking as well as being a safer business proposition.