The coming initial public offerings of AI giants Anthropic and OpenAI could spell a windfall for San Francisco real estate agents, private jet companies—and wild animals.

As AI employees with fast-appreciating stock look to start cashing out, philanthropies are talking to potential donors and preparing for a possible influx of cash. And because many AI researchers have ties to the effective altruism movement, which takes a particular interest in causes that mainstream philanthropies overlook, the organizations prepping for a windfall might look very different from previous charitable waves.

OpenAI is preparing to release a new model family, tentatively using the name “Astra,” with improved abilities to complete long-running tasks, according to three people briefed on the plans.

OpenAI CEO Sam Altman demonstrated Astra to policymakers and regulators in Washington, D.C., this week, ...