It was at first noticeable in streams, but now the developers have officially confirmed that they have removed the Visigothic from the game, with the castle update.
Paradox removed Visigothic from the map of 867, starting Iberia off pre-split between the 1066 cultures, save for Aragonese, which now emerges as part of the creation of the Kingdom of Aragon.
There are a few reasons for this, the main one being that Visigothic was always a bit of a wonky culture, a holdover from CK2’s Charlemagne DLC that made mapping 9th century Iberia very inexact but which added some fun flavor to the region.
Since cultures before 1.5 were primarily cosmetic, it didn’t really affect actual gameplay much, even if it changed history somewhat.
However, the release of the Royal Court Expansion changed that situation, making playing in Iberia a very weird flow. With it, you would start, have one set of traditions, then within a few decades an event shifts your culture and you almost certainly end up with a radically different set of traditions with no feasible way to do much about it.
All of this, plus just being bad history, seems to have clinched it for Visigothic and Paradox had it taken out. As with Suebi and co before it, Visigothic will continue to exist in the files, along with its associated name list, where it remains useable for history and in mods and such.