Ubuntu touch always relied on Android base and its drivers for porting it to other devices. This was done via libhybris. At the time of Ubuntu touch launch, 32bit Android was still prominent and libhybris was 32bit. However, UBport team has now ported libhybris for 64bit devices.
Libhybris is the software project that makes it easier for conventional Linux distributions relying upon Glibc or Musl to access drivers/software built for Android (Bionic C library) software.
So what does it mean?
This means Ubuntu touch can now be ported to modern ARM devices which uses 64bit drivers. Ubuntu Touch as of now has supported official Ubuntu Phone devices and some limited mobile phones of yesteryears.
UBport is already working on PinePhone and Librem 5. But raspberry pi 3 also gets some love as Ubuntu touch can now work on it with the official touch screen support.
Not only this, UBports team is also working to add better support for Bluetooth headsets, and since Mir display server can use Wayland protocol, this allows the user session to be suspended, which saves battery and also improves security and privacy of Ubuntu Phone devices.
Watch the detail Q&A session
The team is also working on Volla phone which you can go and back right now here.