Alex Albrecht's show 4Points on the Nerdist network can be seen as a successor to Diggnation as it more or less picks up on the same format but with an additional two hosts.
New York Magician: Compare the writer's earlier Ethereal Park Ethereal series, which also features magical elements in an otherwise normal New York, along with some Urban Exploration influence. However, the protagonists are very different; Michel is an rich man experienced at all this magic stuff, while the narrator of PE is a broke homeless guy who can't remember his name or past and has no real idea what's going on.
The Whateley Universe is the spiritual successor to the 'Of Masks and Marvels' universe. The author of the latter is one of the key creators and main authors of the former, and they are both superhero universes with transgender protagonists. The main character and main superhero team of the Masks and Marvels world even have expies in side characters at Whateley Academy.
Richard Michael Alvarez, creator of Stupid Mario Brothers, announced that a spiritual successor to SMB called That Stupid Video Game Show. It will feature generally the same characters as SMB but will not have an overarching storyline like its predecessor. Each episode will be self-contained.
TV Trash could be seen as this to Benthelooney's 2009-2011 run of rants, because of The Rowdy Reviewer's characterization, the way he voices his opinions (Fair and less harsh when compared to other caustic critics), less focus on jokes, and more focus on the subject at hand with an occasional joke thrown into the picture. (Especially so, since Benthelooney took a different direction to the way he was before cancellation, when his rants restarted production.)