I don't know about specific Tapas creators, but something I've watched happen a few times in webcomics is super popular creators, who became popular sort of quickly, get overwhelmed by that and pull away from the internet. In some cases they come back under a different name or on a different website or with a different webcomic, and sometimes they never do.
Being a popular content creator can be extremely rough, especially if you get tired or burnt out of the thing everyone wants from you. It's obviously more professional and good to be open with your audience and tell them that you're burnt out, and let them know whether or not you're coming back, but that's also hard to do. Especially in instances where you have younger creators, it's easy for anxiety to take over and they might be too afraid to come back to demands of WHERE DID U GO??? I MISS THE COMIC!!! to let folks know what's going on.