People who want to try the game dont choose to play orks, they have to play orks. If they like the game enough to purchase they will be able to play any faction. It is more likely they will join the "premium" factions for "higher class" gameplay as you wont have to deal with "free to play scrubs". Afterall a certain asshattery is inevitable as with no invest comes no value. In that sense choosing the orks as the f2p faction really helps as they aint the most sane bunch and even the infighting (aka griefing and teamkilling) is covered by the lore.

If you are an ork fan you will then more likely stick with the green machine. If not, then your options are open and 3/4 chance is that you wont stick around.

Essentially there is a danger of orks being too much of a stepping stone faction after the first year of gameplay. New accounts for f2p will allways decline after few first months unless you keep the game fresh or reach critical mass in terms of name recognition.

Stepping stone nature will drain more active and dedicated players from the ork faction in comparison to the other ones. This will impact clan and community building in some extent that will be seen when the game is out.

It just something the ork clans need to deal with, afterall it's normal in F2P games.

Devs have said that they can control the nids to make life harder for the faction that is stronger...

I see where you're coming from, but I think you're overstating it a little bit. See, it's not the entire Ork faction that's F2P it's the boyz class. You'll still be missing the chance to go swinging in as a great Nob, or rocket in with all the hilarity of the Stormboyz. Orkz are a fun faction, more about having fun then combat efficiency and discipline and I think that that'll stick with the F2P'ers as well.

Is that rather new? 'cuz what I heard over the Twitch AMA it wasn't necessarily that the nids would gun for that faction in particular, it would just sort of happen.
Because that faction would be holding the most territory they'd just naturally have to deal with more nids, the larger surface area and all that, but it wasn't necessarily a device in place to make life harder for the current title-holders.

I think Devs taking control of the Nids would be limited to special invents, or if a single faction dramatically outpowers all other to the point that even the nids nagging on the borders of their territory wouldn't bother it.

I can see them doing so, wouldn't actually mind it too much. Just means more good fighting for the boyz. Especially if everyone else is getting out classed that hard.

As for the f2p orks dwindling eventually, it'll happen sure, but that doesn't mean many of them won't join the Ork faction. Here's hoping for glorious burnas

When I think of the devs controlling the Tyranids, I think of them just triggering more infestation events that hinder the leading team more than anything else.

I was thinking full on causing the tide of nids to be start turning their ways towards the steamrolling factions (which is how I why I'm perfectly fine with people controlling nids, it makes it harder for people straight up wrecking everyone else) and tearing up the territory. This leaves the other factions with 2 choices. Head to areas not being swallowed up by a nid horde and push there. Or take the territory left over without hopefully turning the tide back to them.

Will make it quite interesting if that's the case

I like how this oomie talks! I definitely think if we get enough f2p orks we can potentially represent the ork horde numbers. Freebies act as cannon fodder for the big boys.

We'll have to wait and see how it shakes out but I'm still predicting that Space Marines will have the most players even when you consider the F2P Orkz.