I think the speed of confirmation is base on the volume of transaction in blockchain because right now since china closed some of their exchange it has a big effect of redusing transactions.
Whilst it will reduce the transactions a little, I don't think the closing of exchanges will have a huge effect on the number of transactions to be honest...
Most exchange transactions are "off chain"... It's effectively just people swapping numbers in the exchange's database... Only withdrawal and deposit transactions are completed on chain...
And despite the volatile nature of exchanges and security risks, most traders seem to ignore the warnings and keep all their coins on the exchange to avoid transaction fees etc.
Besides, most of the traders will likely just move to a different exchange if their normal one gets closed anyway
