PoS function has not been removed from the code. It has only been temporarily deactivated by enforcing reservebalance= large balance to prevent staking coins in the wallet.

It is therefore still possible to stake (if you edit before compiling) the code or to fully reactivate staking in the future.

Staking (or having 3 methods of block generation active at once) seemed to be causing some issues as the block chain increased in size. This was simply part of a fix to get the chain moving again following multiple 'forks'. Staking does still appear to stall the client on occasions though. I suspect its rather like the old expression "two's company, three's a crowd" ?