It is easy to settle the
legality question by considering an
I flight plan of a 747 flying JFK-LHR
In the worldwide context, most countries don't even publish VFR charts. Closer to home, Greece doesn't. People fly with the 1990s USAF ONC/TPC charts, or they fly IFR...
Also I think there is some confusion regarding emergency pilot privileges (which are unlimited), what is potentially useful, and what is legally required.
When VFR or IFR I normally run VFR charts as a moving map. These are "real printed" charts for the area (so if over Greece I will be on the 1998 ONC G3). On a
VFR flight these will be
current. I do this for emergencies; in case of power failure, for quickly locating nearby airfields, or if flying over the Alps above an overcast (to locate a canyon to glide into). And in the UK this saves me messing around with the paper version of the same chart, which stays on the back seat.
On a VFR flight, one needs to maintain VMC unless one has obtained an IFR clearance, which one is obviously not going to obtain if one has lost the radio. But the captain is 100% authorised to do anything to save his life, including flying in IMC, obviously (can't easily imagine a likely scenario which would not lead to questions being asked, mind you) and then the VFR charts could be very useful for the MSA.
On a Z/Y, VFR charts are obviously needed.
But it is inconceivable that VFR charts could be mandatory on a flight filed as "proper IFR" (Eurocontrol) end to end.