It seems apparent to me that making a living solely with Children's Illustration isn't necessarily possible. Even the three guys who started SVSLearn don't rely upon that particular revenue stream as their singular source of income. It seems almost standard that illustrators have to diversify what they're doing and dabble in a number of different illustration fields. Children's plus comic art, children's plus art fairs, children's plus editorial, children's plus licensing, etc.
As you said, this particular site is focused on one particular segment of the illustration world, but there are classes in the SVSLearn curriculum that cover things like Art Licensing. At the moment, there don't seem to be classes that specifically address Editorial projects. I say "at the moment" because it is clear that relying singularly on one discipline for a livable income isn't practical, and we have had a variety of types of illustration posted on the forums eliciting constructive criticism.
I don't think this particular community is going to ever ever say, "That doesn't have a place here" to editorial illustration as it is clearly a viable addition to their own skill sets. We've had posts about logos, commission work, t-shirts, fabric prints... It's all visual storytelling in the end. It's just about how you define the term. Some would say that's literally what makes illustration different from Fine Art: illustration purposely sets out to make you feel and think specific things--the pieces have a story. Fine Art doesn't necessarily put its emphasis on the story it's telling primarily...
I, too, am very very interested in learning more about editorial illustration, and I can offer you a couple print resources that are opening my own eyes to the breadth and width of what's available in the illustration industry.
Becoming a Successful Illustrator by Derek Brazell and Jo Davies is a book I am currently reading. It discussing the plethora of options in the field of illustration and what specific traits and characteristics illustrators commonly have in order to be successful in each discipline. It is a workbook of sorts, designed to help you find the field that speaks to you.
Illustration: Meeting the Brief by Alan Male is a book focused on helping people learn how to take a "brief" and think through all the options. This is particularly important in the editorial field. It could be very useful to you.
Illustration That Works by Greg Houston is another book focused mostly on how to make effective editorial illustration.
One thing I am noticing is that oftentimes illustrators explore different contexts for their style. Thomas Fluharty is an example of an artist who works primarily in the editorial field but clearly buoys it with children's illustration. I am finding more and more examples of very successful artists that subdivide their website portfolios into different disciplines. In part, this helps differentiate the different styles they have developed to cater to each of those areas.
I, personally, don't know any communities that focus specifically on editorial illustration. While SVSLearn is predominantly about children's illustration, even their own class offerings embrace a wider spread of opportunities. I would suggest you dive right in and share your work--there are a LOT of editorial illustrators on here I'd bet, and you may find some great feedback.