*dusts off my account to chime in*
I've had a few different sources talk directly to me about this....but don't take my word as absolute as always there could be more to it...
The reliability issues stem from the braking system at the end of the ride. They switched metals used in the mechanism that unfortunately is prone to over-heating (if you smell burning at the end of the ride, this is why). When it gets too hot they have to close it to "Reset" the system after it cools off. Safe to assume this could be a reason for an extended refurbishment.
Regarding a retheme: My opinion will always remain that it should switch to Powerline and avoid issues with using "real" bands