When President Donald Trump joined tech executives on Tuesday to tout a multibillion-dollar artificial intelligence project led in part by OpenAI, one question sprang to mind: Where’s Microsoft Corp.?Despite investing almost $14 billion in OpenAI and using the startup’s AI models for its next-generation cloud services, Microsoft was mentioned only as a technology partner in a joint venture called Stargate launched by OpenAI, SoftBank Group Corp. and Oracle Corp. Then, in a blog post, the softwar...