Bitcoin Core devs - the official bitcoin client - refused to include code SegWit2x in the current protocol. The corresponding announcement has posted on the official Twitter Bitcoin Core:

The Bitcoin Core project rejected the pull request for NYA "segwit2x" https://github.com/bitcoin/bitcoin/pull/11128 …

Read more https://bit.news/eng/bitcoin-core-developers-rejected-segwit2x/

Core developers aware of any problem that may occur if segwit2x hard fork be implemented.
But, I think this problem should be can be solved through consensus which segwit2x has gain over 92% support from the miners.
Then, core develoers stated don't want to give more power to miners, not sure what it means but if segwit could resolve bitcoin problems regarding high fees and confirmation time, then no need to another hard fork. At least, we still have 2 months before segwit2x hard fork will be implemented, at this period, segwit should be able proven itself as reliable scale solution.