I just see if the adds are too far apart, as in everyones main character is at basically most evolved they can achieve 2-3 years down the road and a new faction does come in the wave of players looking for something different will be more than anything, like WOW with their expansions an Warhammer Online when they launched choppa and slayer classes, remember going down a tier 2 days after the launch to help the 80 slayers running around complete quests because there were no healers around, it was a sea of angry little readheads, I felt like I was running an orphanage.
Its not up for debate in my eyes really, the devs have stated multiple times now that their plan is to include all the factions as the game goes on. So having only 4 is not happening.
i want to see, an in-game event, where the nids launch this GIANT invasion of a planet, and all the factions must ally together to survive, and they are all at some big base on a mountain, the last base on the planet, and as they sit there and wait, they see a black line appear on the horizon, and then the line is revealed as a massive Tyranid horde scaling the mountain, and las and bolter fire (and whatever the Eldar shoot) flying at the wave, alien bodies fall by the millions, but this does not slow the wave, not one bit, and we should have to hold said base, all players, from every faction, working together to defend this one, last base, and if we win, the factions would all get some bonus, and everyone who fought in it should get some little armor decoration or something basically stating "I WAS THERE!" and it should only be available to get by fighting in said event, and if we fail to stop them at the first world, then maybe instead of going back to fighting each other, the nids push on and on until they are stopped, meaning if they are not stopped, they will conquer worlds we have already fought over, taking away those bonuses, until they are stopped
There was talk if Tyranids would be able of winning the campaign as an NPC I cant remember the exact response but I believe the Devs had a look of shock amonst them that it was even suggested
I doubt the tyranid will play a massive role in the open world. They might "infest" bases or autocap objectives in order to moderate balance between factions and they'll be around in the limited PvE content. But i really realllllly don't think we'll see hordes of NPC opponents waging epic war against the players on the open battlefields. That'd be super complicated for a game like this
More just making this so they can see what they could do first to keep people happy, of course all factions would b ultimate goal, but I think they realize the perfect blend of subscribers and balance as well as simply what they can accommodate at this time makes that unlikely to even put anywhere but on a white board that hangs out in a back room where pens, staplers, and squat design sketches are kept.
Someones being overly pessimistic. Going by that a large amount of actual planned content can be relegated to your so called forgotten white board due to a thousand of possible reasons. Also how are you drawing the "at this time" sentiment on a game to be released in 2 years which hasnt even started its marketing machine in full swing?