Just my opinion - no, the pending devaluation isn't a killer in itself. In fact I'm sorry to say we're going to see more moves like it from more programs. The economy is tight and I suspect many companies that are cutting travel now will not be restoring it in the future if times get better. Inflating the 'currency' is an escape valve the programs are going to use to get out from under the point liabilities - facts of life.
That said - I do think that this latest move is creating too much compound annoyance on top of everything else. The upgrade benefit is fading thanks to NOR1 and HHhonors is far behind its competitors in offering promos. Other programs are looking more and more attractive by comparison.