A Bitcoin Cash (BCH) upgrade that will both increase block size from 8MB to 32MB and add or reactivate Bitcoin script operation codes (Op codes) has been activated today, May 15.
The hard fork used the Median Time Past (MTP) for initiation, going live on next block after the MTP timestamp of 1526400000 at 16:14 UTC.
Bitcoin ABC, a Bitcoin Cash full node implementation, posted on April 1 that the Bitcoin ABC 0.17.1 full node upgrade testnet was available, noting that all BCH full nodes needed to upgrade and that major exchanges and wallets were being notified. BitcoinCash.org also wrote that this is the first of several planned upgrades for the currency.
An explanation of the new upgrade on Reddit says that the upgrade is “paving the way for future adoption as well as new functionality being added such as op codes.” User Steve Shadders-a co-author for reenabling disabled Op codes - posted on his blog that the reactivation of formerly disabled Op codes is compelling to developers and could bring value to the BCH economy.
The arguments against an increase in block size include making operation of full nodes more expensive, leading to less decentralization of the network, as well as lower propagation speeds, according to BitcoinWiki.