If you believe that "cleared ILS" permits descent to the intermediate altitude, why do you not believe that the "direct to KELON" permits descent in accordance with the arrival?
"Cleared ILS" when being vectored is given at a suitable point in the procedure where the flight has been placed correctly by the ATCO on an intercept with the intermediate phase of the approach and is in a position to descend to the level appropriate for the start of that phase (note that it is normally a level phase).
I never cease to be amazed by the number of pilots who are being vectored at 3000ft by ATC and on the 30 degree leg at 13nm are "clerared ILS" which triggers some irrational desire to dive as quickly as possible to 2000ft (the published platform level) despite the fact that they can establish on the LOC and have the required 2nm of established level flight before GS intercept - at 3000ft!!!!
Cleared direct to KELON is a lateral clearance alone and for example just because the minimum level on fro example an airway to KELON (which could be your IAF) is 2500ft you are most certainly
not cleared to 2500ft simply becasue the ATCO cleared you to KELON.
As I pointed out - yes it is terrain safe and in this case it would be airspace safe (probably) but is it safe against opposite direction traffic then only ATC knows and they have not cleared you to change level.
When in the procedure eg in the case cited in the hold or at the IAF at FL80, ATC can not clear you for the procedure unless there are no other flights below you in the procedure. However, when 20 miles away inbound from say the south east at FL80 they can clear you to the IAF and clear you for the approach (becasue the procedure is empty) but climb a departure to FL70 straight at you.
They have issued you a clearance for the ILS procedure. They have not issued a clearance to descend until on that procedure.
Yes FL80 is very high to start the procedure and would perhaps be uncomfortable if doing it direct and not via a shuttle. However, until ATC clear you lower (which they may have planned) you do not know that it is safe to do so.
I will repeat that;
until ATC clear you to a lower level you do not know that it is safe to do so
Safety first.