To start this thread, here is a link to the officially supported devices
https://webos-ports.org/wiki/Devices
If you want a new webOS phone, then you are currently looking for a LuneOS phone - or more specifically, a phone that can run LuneOS. While it's not impossible that some other group or company will release a webOS or LuneOS phone, the likelihood is that those wanting a webOS phone will need to install it on a device not specifically designed for it.
The basic requirements are that the device is either "open hardware", so that various operating systems can be run on it or that it is an Android phone with an unlockable bootloader. This means the hardware drivers are available and a basic version of Android can be installed as a base for the LuneOS UI. The same is true for tablets, though it is possible to run LuneOS on the original HP TouchPad tablet and prototype versions. This is because the TP was originally intended to be an Android device until HP bought webOS from Palm. Some prototype devices were found with Android installed and this allowed versions of Android to be dual-booted with webOS (or installed solely). It is these Android hardware drivers that also allow LuneOS to be installed.
Of course, LG continue to develop webOS as a commercial system, but they have previously rejected releasing a new mobile phone and in fact appear to have stopped producing mobile phones completely. But they may bring out a wider range of webOS devices that maybe of interest to the community.
So if you know of an upcoming webOS device from LG or another company or if you spot hardware that could potentially used for LuneOS, post here.