Except it's not, not even close. That's like me saying I think an entire country is mine and meaning that it is, or calling dibs on something and still not getting it. The only thing the Jailer has control of or can manipulate is The Maw and anything in it, currently. It might expand later but right now he doesn't
Except none of that anima is going to him at all. It's all being funneled to the convenants to separate chambers that won't make it to the Maw. If he was later to invade these realms and break the containment chambers then sure. Also, nothing in the maw indicates he needs anima or wants it. He just wants souls to fuel and become his weapons. Even the "mobs / weapons" in the mob don't contain Anima and are known to contain Stygia as Ve'nari mentions.
He did lose Anduin. He had each of them chained up and in cages. Jaina kept escaping only to be captured again along with Thrall. Anduin was chained up and protected by another lesser jailer. He even thought he had killed Baine. We freed each one of them and they were recaptured later on.
It's not that he was "more interested" in what we did. He was there to reclaim what he had taken and in the process saw us activate the waystone which he found interesting. Doesn't mean it changes his plans or was his intention at all. He saw what Anduin was capable of in a weakened state and found that to be a lot more interesting and how he can mold it to because his weapon.
That can be your interpretation but nothing story wise has even came close to giving off that vibe or stance. Arthas in Wrath it was known that he always wanted to add the best and he never strayed from telling us he wanted us in his armies.
If anything, I've gotten a different feeling altogether. Right now the story has shown that the four covenant leaders we see (as there are more realms, but the story mentions how these four did it) have imprisoned the Jailer (I think they said how, but I can't remember exactly how off hand). We also know that they created the Arbiter to replace the Jailer's original role. Those are the definite things and the rest is mostly speculation.
Though one thing I've felt is that the vibe given off is that the covenant leaders we see could possibly be corrupt and felt like the Jailer wasn't giving them what they wanted so they condemned him to the Maw. Then they created the Arbiter who would do their bidding essentially.