That's why I wrote "still". AFAIK both C++ and C now expect integers to be in 2s complement and made unsigned overflow 'defined', but at the same time kept signed integer overflow as undefined behaviour.
Hmm true, now I wonder what the standard change that integers are expected to be in two's complement format even means in practice when the only important related UB (signed overflow) is still UB. Guess I'll need to read the original proposal again.