On Friday (September 6), Hudson Jameson, Community Manager at Ethereum Foundation, confirmed that the "Istanbul" hard fork is expected to be activated on testnet Ropsten on or around 2 October 2019.
Ethereum's core developers finalized the list of Ethereum Improvement Proposals (EIPs) at an "All Core Devs Meeting" (which is a "a technical meeting intended to bring together various Ethereum teams who play major roles in determining the direction of the protocol") held on 15 August 2019.
As per previous meetings of the group, which comprises a diverse set of Ethereum stakeholders, the plan is for Istanbul to be executed in two phases:
phase 1: this consists of six EIPs; estimated to go live on the Ethereum mainnet in October;
phase 2: this consists of those EIPs, such as the proposal to make Ethereum more ASIC-resistant by moving to a Programmatic Proof-of-Work (ProgPOW) consensus algorithm, that need "further testing and deliberation from core developers."