My understanding is that it has more to do with the general direction of observability. The agent code was always open, we frequently accepted PRs from the community when I was on their Ruby agent team, but they didn't use an open source license.

We're public so I probably shouldn't guess too much about the motivations beyond the explosion of interest in observability/kubernetes/cncf, but I do know there has been support for open sourcing these for a long time within the company and I'm glad to see it finally happen.

disclosure: I work at NR but my opinions are in fact cake and should not be used to make investment decisions (seriously that is a terrible idea I mostly invest in LEGOs and Magic cards)