An earlier version of this post said Snowflake, BigQuery and SQL Server were next. All three ship now, along with ten others, so here is where each warehouse stands.
Forewarden now connects to 13 warehouses. PostgreSQL, SQL Server (including Azure SQL), Oracle, Trino / Starburst and ClickHouse have run end to end against real or Dockerized instances. Databricks, Snowflake, BigQuery, Redshift, Synapse, Fabric, Athena and Teradata are in preview until they have run against a live account.
What preview means
For a preview warehouse, the dbt profile Forewarden writes is validated against the vendor's own installed dbt adapter, and the connector returns the vendor's real error from a test endpoint. None of them has run a dbt build against a live account yet. If you connect one, give it a least-privilege role and tell us what you see.
Features differ by warehouse
Every warehouse runs dbt Core through its own dbt adapter, with scheduling, runs and the catalog. Compare, Canvas, the semantic layer, Slim CI and warehouse import depend on the adapter; the product page has the full matrix. Warehouse import supports Postgres (tested) and Databricks (preview: not yet run against a live workspace). Only PostgreSQL, Oracle and ClickHouse enforce read-only mode on the warehouse side for ad-hoc SQL; elsewhere Forewarden's statement guard is the only barrier.
If your team is waiting on a preview warehouse to move to tested, tell us. It is a real input into which one we run against a live account first.