As per this doc, in order to create a connector to Microsoft Teams, I'm supposed to publish it to the store.
If I am to build an internal-facing, highly company-specific bot that notifies of specific events, which is obviously supposed to be private, is there a way of building it?
Am I missing something here? Is it really necessary to publish it to the store in order to have it working in my company's Teams account?
As per this helpful link,
When you're ready to share your Microsoft Teams apps, you have three options depending on who your target audience is.
Upload your app directly If your app only needs to be shared to your team, or a few individuals in your organization, you can share your app package and upload it directly.
Publish to your organizational app catalog You can share your app with your entire organization through your app catalog.
Publish to the public app store If your app is for everyone, you can publish it to our public app store. Depending on your goals, you might be eligible for marketing and sales assistance.
So, in this case, uploading the app directly is the answer.