I know it's a subtle distinction, but I'd suggest avoiding the term "give back".
The AGPL requires that source code be supplied to users of the system. In other words "code flows down-stream". There us no requirement to flow the code "upstream".
Now sure, you might become a user of their service. Or you might get a user to pass the code onto you. And that may have the effect of you getting the changes they made.
But they are not "giving back", and they have no duty to do so.
I know it's a subtle difference, but I think it's helpful to be specific when it comes to legality- it avoids misunderstandings.
The AGPL requires that source code be supplied to users of the system. In other words "code flows down-stream". There us no requirement to flow the code "upstream".
Now sure, you might become a user of their service. Or you might get a user to pass the code onto you. And that may have the effect of you getting the changes they made.
But they are not "giving back", and they have no duty to do so.
I know it's a subtle difference, but I think it's helpful to be specific when it comes to legality- it avoids misunderstandings.