Did they ever start? <- OK we got that joke over quickly. Now I don’t have an announcement from Vox Day or the Castalia House blog to back this up but the outfit that Day was claimed would overtake Tor Books soon has pretty much dried up completely.
The last blog post at Castalia’s blog leading with “Castalia New Release” was in November 2018 and was Day’s non-fiction riposte to Jordan Peterson. ISFDB has only one entry for Castalia in 2018 (Nick Cole’s republished Soda Pop Soldier) and while I know they are missing some titles (e.g. Cole’s sequel to that book from 2018), it is a sharp contrast from 2014-2017.
John C Wright’s “Nowither: The Drowned World” was published in 2019 but the series has shifted from Castalia to Superversive Press. Newer writer Kai Weah Cheah published a sequel with Castalia early in 2018 but his more recent books have been with Russell Newquist’s Silver Empire.
I may be wrong but I think the most recent book of any kind (other than comics) Castalia has published is the latest in its series on composting & gardening (https://www.goodreads.com/en/book/show/45728752 )
This maybe connected to the problems it had with Amazon earlier in the year (http://voxday.blogspot.com/2019/01/amazon-takes-down-castalia-house.html ) but it looks to me that they just aren’t offering much to authors other than a name with a dubious brand. Maybe the biggest little sf publisher you’ve never heard of tripped over its own jackboots.