After having listened to both of The Letters Page episodes about the Freedom Five tv show, I made an account to ask this question. What would we need to do as a community to have Netflix, or another streaming service, take notice/interest in making an actual cartoon series starring our favorite superheroes? Who do we need to tweet at to make this happen? How would we pitch this (assuming GtG would be down)?
I wouldn’t think fans would have any chance of making this happen by going straight to producers. Find an animation studio that wants to make it happen first. And I don’t think mere tweets will accomplish much.
Honestly, I don't think it's realistically feasible at this point. There aren't that many great super hero themed tabletop games- and there were even less when Sentinels first released. However, there's a plethora of different super hero themed cartoons out there, the market for that is already overssaturated. This makes it far harder to pitch.
This is a good point. The IPs saturating said market are also what Sentinels is made in homage to; there's going to be a lot of obvious overlap, especially right at the beginning.
Honestly, for all that this community is large and vibrant, Sentinels is a very niche property. I think people would enjoy it, given a chance to experience its full depth, but convincing anyone whose business is money that it's worth doing is a tall order, to put it lightly.
I do hate saying that, just because I know how exciting stuff like this is to think about. 
Yes and no.
There's a fair number of Marvel/DC cartoons out there, but original property superhero cartoons is a question I'm not sure of.
While I'll fully admit that the list is a lot looser with the concept of "superhero" than I'd like (Scooby-Doo and Star Wars are on the list?), if you go through the recent years manually searching for those that are still present, you'll find there's quite a number of them: List of superhero television series - Wikipedia
And they have seperate pages for Marvel and DC.
Yeah, that's why I asked here, since I first looked through that list and found it unhelpful since almost all of the series listed that I've heard of I wouldn't view as being superhero series. (Transformers and Mega Man? Really?)
I think out of the ones currently running that I know anything of, there's maybe six? I'd consider superhero stories. And two of those are reboots.
Interestingly there's not as many Marvel or DC series currently ongoing as I thought either.
There might be some other problems with the obvious similarity to other super heroes. While DC and Marvel both steal from and respect each other, often having heroes who are essentially the same person, it might be a lot more difficult for similar heroes coming from card/miniatures/RP games. Although I liked that the Oblivaeon comic was short and to the point, perhaps it would be best if they started with actual comics.
I've even thought of a couple short strips, one involving a craft brewery I go to, with Fanatic asking why she can't get a growler of a beer called God's Wrath.