Annex14
Plse check aterpster # 44 link to the approach map. You will see there is no procedure altitude of 2000 ft at the IAF ZEDAG.
No argument there and the charts are familiar to me.
Only proposing that pilot knowledge of MIA might have been helpful.
Your point is a good one, though.
Since it appears that the crew ignored or failed to properly consult the approach chart -- and appeared to place sole reliance on the ATC clearance -- it might be a stretch to assert that they would have displayed any other available source for minimum off-route altitude.
However, it remains to be seen whether ATC radar was ever terminated. It sounds as though the flight was still receiving radar services at the time the erroneous ATC clearance was issued.