I'm just going off of what I've heard as well. AS Truthslayer above mentioned what CBOAT has stated on the issue. CBOAT is a user on the Neogaf forums who leaks a lot of info on things and is right a very very high % of the time. He hits it on the head often and frequently enough that when he says something you can pretty much believe it. So while it is technically rumor, his history gives him the credibility that believe him.
Basically from what I understand with the info that is currently out and know, if an indie dev wants to self publish on the X1 they have to pay MS like $100 fee to unlock debug mode on their X1 (which allows them to run unsigned code on the system which they would need to do to get their game running on the system). They would be restricted in the amount of RAM they are allowed to use on the X1. While any other dev that is not self published will have access to 5GB of RAM for their games, a self publisher indie will only be allowed 3GB of RAM. Also, they will be regulated to the Windows 8 app store instead of the Xbox Live Arcade store where other games that have a publisher will be listed.
So MS from what we know, now will allow self publishing from Indie's but they are limiting the amount of the system they can use (that other developers with publishers have access too) and are putting them in a different part of Xbox Live not with the other games (that have publishers). Which means besides being handicapped on a tech level, they are being punished by having their games hidden somewhere else away from the rest of the other games.
The multitasking and stuff you mentioned has nothing to do with this as that is part of the X1's OS's and MS has a reserved amount of resources for it that no game developer can touch. MS has stated that the X1 will reserve 3GB of RAM for itself (The PS4 we do not have a number on yet, but it is probably between 1GB-1.5GB from previous info we had), we don't know how much of the other resources are reserved just for the system but it is rumored that 2 of the cpu cores and around 10% of the GPU are reserved for the system itself (same rough numbers for the PS4). What does that mean? So when they (system makers) announce the specs of their consoles, those are the specs of the machine, but they reserve some of those system resources for the machines use only thus the amount of resources/specs available to the developer is less than what the overall amount of the systems specs are.