My bet: it is very unlikely the 5ii will get official support for the foreseeable future. There certainly has been no indication of that even possibly happening, unlike the 10ii. The 10ii itself is a year old so if support for that is taking the time that it is, I can’t imagine Jolla supporting any other current phones, unless the manufacturer gets on board and licenses SF.
I would not get a 5ii in the hopes of official support (and I have a 10ii in the hopes it will get support).