You may (or may not) recall the #Freenode takeover mess. However, thanks to #IRC being an open and widely supported protocol, many projects migrated to #LiberaChat with as little disruption as possible.
Good news is, your walled garden is unlikely to suffer the fate of Freenode — because it already is there, from day one. What are you going to do when your project suddenly gets banned and you lose access to everything — including all the data that you shouldn't have kept there in the first place? Of course, come up with some corporate bullshit of "join us on our illustrious journey to the next walled garden, and don't forget to install another 200 MiB privacy nightmare app not to be excluded from our community".