Small scale GPU miners are the most affected here specially for those who live or mining in a country with high electricity cost
Many block-chain will become POS or Masternode. At the end, Bitcoin will become the only mineable crypto.
I have 2 problems with your 2 statements.
First, small scale GPU miners could easily survive as long as they build rigs geared towards efficiency. Large farms need to pay overhead for warehouse fee, taxes, maintenance, and all that while a simple GPU home miner can maintain his rigs thru teamviewer, all for free.
It is hard to imagine that bitcoin will be the only mineable crypto, or even the last mineable crypto. There is no basis for your claim while on the other hand mining bitcoin is already less profitable comparing the most efficient bitcoin miner with the most efficient altcoin miner (regardless whether GPU, ASIC, FPGA).