Black Knight Irios
Explorer
The way I see it, even powers that do not allow a save under certain conditions cans till be saved against - someone just has to give you a save. There are many powers that do this, as does a DC 15 Heal check.
This solves many of these issues.
You can save against powers that a save can end and if you get an extra save from any source you might get rid of the effect sooner.
But if a power does not say that 'save ends' its effects, even if you get a save it will do nothing if you succeed.
But if you mean there are effects that you can save against only if someone grants you a save, then there are some ways to get a save from an outside source (ally/etc.). And you are right.
PHB P 278
Durations
There are given conditional durations none is permanent.
Even the pre-update version does not spell out permanent which would lead to an exception to the rules. It is described as (no save). (no save) is not a duration. It just states that you can't remove the effect with a save. So the default longest duration that is given in the PHB is until the end of the encounter.
So arguing that it was meant to be permanent is not backed up by anything except some wishful thinking of some DMs.