There appear to have been a few online communities that have tried to continue the Legends timeline through fan works. The ones I can find are:
However, none of these appear to me to be active. I imagine that there are fan-continuations of Legends scattered across the web, but it does not appear that there is an active online community unifying it.
New, Officially-licensed Legends Content
While not part of a fan community, there is new officially-licensed Legends content being created. New releases from the Star Wars games produced by Fantasy Flight Games have continued the Legends continuity since the creation of Disney canon. Notably, the X-Wing miniatures game has created several ships, which are part of Legends continuity. Similarly, The Old Republic MMO (which is definitely in Legends) has had new releases since the Disney canon policy, such as the 2015 Knights of the Fallen Empire expansion.
In both cases, these are new releases to games there were canon (technically, C-Canon) at the time of their initial release. In other words, they were canon before Legends existed. Continuing to build off of this in future releases means older products in the line are not invalidated. I guess you could say that these releases were "grandfathered in".
It's worth noting that it's usually to their advantage for these games to be set in Legends, since it is very rich with existing material that works well with their games, and are already recognizable to Legends fans. Want to shake up X-Wing with a new TIE Fighter that has a gimmick? How about the TIE Phantom, which has a cloaking device. Need an underworld villain for an Edge of the Empire scenario? Tyber Zann is an excellent choice.
Note that although they are adding new content, both Bioware and Fantasy Flight Games aren't telling ground-breaking new stories. They aren't revealing what Luke and company did after the events of the last Legends novel. They are creating content to support their game lines first and foremost, building off of prior work in the rich Legends continuity. But it is indeed a continuation of the "Legends" timeline, and probably the last continuation from a licensee that will happen.