Adrien My definition would include reliable backup / recovery options that notify at least upon failure. If this was some Github project I would have no expectations. However, its marketed as "Production Ready" and yet until recently you had to come up with your own backup solution and now doesn't notify you on backup failure.
Untestable silently failing server backups.... Yet its "Production Ready"?
I wouldn't even release a business critical desktop app that doesn't have AT LEAST clear backup/recovery documentation. And if it had backup features its certainly not going to fail silently unless its BETA. When critical features are missing important things, it makes you look amateur and not production quality.
I imagine the backup issue doesn't affect large hosts much because they run baremetal and have a lot more flexibility in terms of bootable restore, drive swapping etc. However, if you host with VPS's you only get provider backup/snapshots which are notorious for having issues and being untestable.