it looks like an interesting concept, I would love to try it !
I work on B2B SaaS applications for medium/large industrial company and I don't think open source would improve your security posture for this type of client. IT departments have to evaluate vendors against a set of criteria and you pass or fail. if they are worried about the confidentiality of their data, then another approach would be to let them run your chatbot in their own cloud environment (or on premises).
this approach is appealing for a lot of companies. for instance, just looking at Azure, if you make your application part of the MS Transact program, then the client would simply pay their monthly/annual azure subscription and your license would just be a line item on it. this may seem pointless but large corp tend to negotiate deals with cloud providers and negotiate a better deal provide they spend a certain amount per year. if your solution helps them achieve this amount, it's very appealing
Beyond that, you can work on complying with SOCII or other programs
One reason we failed to convince companies were privacy and security.
Business is like dating. They're just "not that into you," and will offer the most ready response to make you go away.
I can assure you open-sourcing your chatbot won't change their minds. It's not like they have personnel eagerly waiting to vet your code for vulnerabilities.
curious - how does "Teams" vary from "Microsoft Teams"?
Are you a software company selling software? Then probably not. Are you a software service company selling the convenience of running your software for a relatively competitive price? Then yes.
There are some who will just grab your software and run it locally, but those people were unlikely to be your customers anyways. And then there are those who will pay you to run the software so they don’t have to spend their own engineering resources on it. These are your customers.
Unless something in your code is secret or the software is so trivial to run reliably and keep up to date I see no reason to keep most SaaS software closed source.