Will AI replace Vagrant developers?

No, AI will not replace Vagrant developers. While AI might help with certain environment setup tasks, including automation and suggesting particular configurations, Vagrant developers bring in acumen pertaining to designing, managing, and debugging of complex development environments. A Vagrant developer has to understand the application dependencies and requirements and tailor the environments for these, which requires a lot of insight and problem-solving beyond what AI is currently capable of.
Although AI can enable the automation of certain tasks, like environment configuration or optimization of resource usage, only human judgment can establish and maintain consistent, reliable, and well-integrated development environments which truly satisfy project-specific needs.