My company (I'm not part of the team that's responsible for anything AI related) has MCP's for Jira, Confluence, Mattermost fork and a few other integrations.

I have no idea about MCP vs API question but I always assumed that the whole point of MCP was an abstration between the model and the tool\service.

As in model does not have to know about a certain API (not to mention a particular version of it) to work with a service.