The ADF is no longer a required carriage item for enroute IFR in CAS.
The "problem" is that many
approaches involve an NDB as a locator, and if you fly procedurally (no radar) then you need to be able to deal with it there.
Of course nearly everybody uses a GPS to fly NDB (or VOR) approaches, but that is a different debate
To say that the IMCR does not need to teach NDBs is a tacit acceptance of not only universal GPS use but also of the US-style GPS substitution for the ADF which is not
AFAIK formally available anywhere in Europe. I have no issue with that, because that is how I fly, but I do wish they became open about it instead of beating about the bush.
I am not an instructor but if I was teaching the IMCR I would make sure the student can fly every approach plate I stick under his nose