Bun and Deno's goals seem quite different, I don't expect that to change. Bun is a one stop shop with an ever increasing number of built-in high-level APIs. Deno is focused on low level APIs, security, and building out a standard lib/ecosystem that (mostly) supports all JS environments.
People who like Bun for what it is are probably still going to, and same goes for Deno.
That being said I don't see how Anthropic is really adding long term stability to Bun.