As one who is highly critical of the BUSL and especially of companies switching from Open Source licenses to the BUSL, I want to chime in a bit on this.

First of all- Thank You. Thank you to Sentry and the people there for making Sentry and making it originally Open Source. Thank you for continuing to make it eventually Open Source. Thank you for your continuing financial support of Open Source. I should have been more nuanced in my comment above, as Sentry only abandoned Open Source for their core product(s) and continue to contribute to other open source projects.

I don't believe Sentry "owes" anyone continued open source license terms.

I believe strongly in the value of the ability to fork. This is best for both companies and their customers. It allows both to pivot to new models. This is why I promote open source and insist on it for any core infrastructure or applications within my business. The freedom to fork has to be available to the community or any subset thereof, and viable. This is the weakness of the BUSL- because it prevents the community, or a subset thereof, from pursuing a key source of revenue to fund a fork.

I also really appreciate the business challenges of running any business, and especially an open source business. I believe there are many viable avenues to doing so. Community, product quality, support, and freedom are all critical selling points that open source companies have to do a better job of promoting and leveraging. I am willing to talk to anyone at Sentry or any other company considering the BUSL about strategies to make money and to avoid "heretical" software licenses. :)