Looks like you called it. Seems the container image(s) default to a subscription plan (“Starter”, free for <50 users) but apparently you can revert to the “Community Edition” which gets rid of it.

Found this post over at the place we no longer speak of :

Hello, I’m Gabriel Engel, the founder of Rocket.Chat. I want to clarify that there is no new limitation for community use. We’ve recently introduced a plan offering all enterprise features for free to groups with fewer than 25 users. For those with more users, you have the opportunity to try the enterprise features. After the trial period, the system will automatically revert to the community version. However, you have the option to bypass the trial in the admin settings. I emphasize that we are not imposing any restrictions; instead, we’re providing the enterprise version free to small teams and inviting larger teams to experience it. Let’s view this as the positive initiative it is. For more details, please visit our forum: forums.rocket.chat/t/…/18736

In the admin settings for your instance you can go to the “Subscription” panel and down at the veeeery bottom is a “Cancel Subscription” button (I’m on the free “starter” subscription, apparently). I’m assuming that’s how you back out of it.

Once I have a chance to warn users that I’m about to do something potentially dramatic, I’ll test it out and see what happens.