I have worked on FADEC software for Large Civil Aircraft:
In the software that I have worked with, when thrust reversers have been commanded, engine thrust cannot be increased until the software is absolutely sure that the mechanism is locked in place --- exactly to prevent this sort of accident.
FADEC has been around for 30 years, and these sorts of common-sense protections are a big part of the reasons that reason that it exists. If you can be confident that you know the position of the TR mechanism, then it's a very simple task to limit engine power to some idle while the mechanism is in transition -- I am somewhat surprised that a extremely modern engine does not have this functionality: I can vouch for the fact that engines had it 20 years ago.
I also find it hard to fault the pilots for the crash given that the TRs operated so counter-intuitively: Thrust Reversers are designed to slow a plane down. Instead, they made the plane speed up. That means they worked the exact opposite of how they should have done.... I'm not sure if there is a way they could possibly have behaved worse in that situation.