Putting on my tinfoil hat. Did Anthropic even buy Bun because they actually use it or was it just an excuse to lob ridiculous PRs at things with at least a little bit of credibility behind them. Their way of trying to set a precedent for accepting AI code into bigger open source projects.
The author has huge online following, and influence over developers. I don't doubt the author is genuinely interested in this, but the employer definitely is supporting this too.