Ok - let's look at the limitations of the different camera types for learning with.
I will assume that, for maximum learning potential, that even if a P&S, Compact or Bridge camera is suggested, it will (or should) be one that allows Manual, Aperture Priority, Shutter Priority and Program control, in addition to Auto.
Phone:
the tiny sensor won't allow any useful experience of Depth of Field
the camera is unlikely to be able to be controlled manually, or even semi-automatically
limited focal length range (may even be digital zoom only)
jpg only
P&S, Compact and Bridge:
the small sensor won't allow much useful experience of Depth of Field (DoF)
some may shoot RAW, allowing more PP experience to be gained
Interchangeable lens DSM or DSLR:
with a medium to shortish fast prime lens, to maximise DoF experience, plus
a standard kit lens to learn the disadvantages of average zooms and a range of focal lengths, plus
ideally/optionally a kit telephoto to give experience beyond 55 or 70mm
I sure hope Jeff remembers to come back and read all his replies!
If anyone needs an explanation of why I have said any of these things, just ask.