> The lesson I’m taking away from this is just use a license like they’re using now from day 1.

Sure, if your whole business model is “sell a SaaS”, then making the whole offering an open source product that is simple for other people to host and offer an equivalent (or, if integrated with other offerings you don’t have, often more compelling) service is a bad choice.

But people choose open source licensing for a reason, and against competing software, a proprietary license can be a negative feature which makes it harder to grow mindshare and prove out utility.