For a (usually) complete list of exchanges that allow for trading Bitcoin, Ethereum and and a plethora of other currency pairs at a reasonable volume, select a currency and click the 'Market' tab on Coinmarketcap. As an example, for BTC see here and for BCH (Bitcoin CasH) see here.
If you you're looking for specific news and/or statements from an exchange not listed below you can use the technique above to find the relevant website and look for the corresponding news section, usually listed under a 'blog' or 'support' section.
That being said, below is a incomplete list of recent statements around the blocksize and other potential fork debacles. It'd be interesting to archive any statements so far and see how exchanges do (not) live up to their statements and scrutiny in light of recent events.
In no particular preconceived order:
Trade long and prosperous!