> Other parts of the infrastructure used by Mir originate from Android. These parts include Android’s input stack[11] and Google’s Protocol Buffers.[12] An implementation detail in memory management shared with Android is the use of server-allocated buffers which Canonical employee Christopher Halse Rogers claims to be a requirement for "the ARM world and Android graphics stack"
I think Canonical wanted to be able to easily port Ubuntu to Android devices in the future. Will that be possible with Wayland, too? I think that's a pretty important aspect, because Android is the new "Windows", and there will be a ton of Android devices in the future, and just like Linux adapted to working on Windows machines, they will need to adapt to work on Android devices very well, too.
Mer achitect - Carsten Munk started the libhybris project, to allow using binoic drivers for Android with normal glibc Linux system. Mer is the core used in Sailfish (and Carsten Munk works for Jolla as well).
I believe that a lot of the Android integration parts they rely on were developed by a dev who was later hired by Sailfish, and who are as noted above, planning on using Wayland.
https://sailfishos.org/