All very true
How much of the revenue do they keep from something like Helldivers 2? Especially if there will be DLC and in game purchases?
It's a per case scenario, every publisher normally has their own formulas with different approaches, or even a same publisher depending on the IP or dev may change it.
But the typical scenario is that the publisher funds all the costs of the development and marketing teams (in this case Arrowhead being one between a couple dozen teams or so working in Helldivers 2) until the game gets shipped.
When released, 100% of the revenue left after taxes, refunds, chargebacks, retail/store costs, shipments costs, server costs, etc goes to the publisher until they recoup 100% of the investment they made. Once it breaks even, there's a publisher vs dev revenue split that often is 50%-50% or 70%-30%. In cases of smaller games specially when the publisher didn't fund the game it's often 70%-30% instead.
In some rare cases -cheaper ones, or when the publisher didn't fund the game- that revenue split starts at the start or when they recouped a certain amount of money, not waiting to.
In case of GaaS, in the game budget it's also included a portion of the post launch development, normally its first post launch year. If the game recouped the investment and is profitable then every year post launch they review their post launch roadmap according to the results of the previos year and part of the revenue to fund the next year of servers and support.
Meaning, as the game revenue declines they also spend less in the amount of post launch staff people working on it, eventally not havin anyone working on it, plus also doing some stuff to spend less in servers. And at some point the games doesn't generate enough and they end shutting down the servers.
When I say game revenue I mean revenue from game sales + passes + DLC + MTX + merch etc., Every dollar generated by the game in any way and source.
I estimate that they should be around 10M units solds combining PS+PC. Regarding Warbonds and microtransactions their revenue should be way under the average in GaaS, because the in-game economy is very generous, relaxed and not aggressive at all.
But they won't care, because 10M units sold at 40 bucks each already is a ton of money. The game, including bigger than expected post launch support for let's say 5 years has been already recouped and they are genereting profit. So any game sales, warbond or MTX sales going forward durin the next years will be profit.
The game, at least in Steam, also features an insanely successful user retention bigger than most GaaS hits. The percent of users that it loses after the first day, week, two weeks, a month is super small. And amount of time spent in the game is also larger than usual. Exceptional user retention implies long term game longevity and better sales of MTX and Warbonds in the long term and in average.
Meaning, on average each player will spend way less on warbonds+mtx than usual per day or month. But they will stay way longer, that would compensate it making its addons revenue better in the long term.
And in any case, even if their addons revenue sucks they'll have minimum $40 bucks per user, which is way better than the average F2P player pays.