Of note, they mention (ordering/emphasis mine):

> We remain committed to Zoekt, the open source code search engine, and will continue to upstream changes to it.

https://github.com/sourcegraph/zoekt

> The source code will remain publicly available.

> Individual devs will still be able to use Sourcegraph for free on public code at sourcegraph.com and within our self-hosted free tier on private code.

> Very few individual devs or companies used the limited variant of code search that was open source. The vast majority (99.9%+) used the enterprise product. Maintaining two variants going forward was a big burden on our engineering team that had very little benefit for users.