Are iShares & GBTC 'greenlighting' bitcoin exchange-traded funds?

Could you please elaborate on the notion that iShares and GBTC are potentially "greenlighting" the introduction of Bitcoin exchange-traded funds (ETFs)? Are there any recent developments or announcements from these companies that indicate a shift towards embracing bitcoin and its derivatives as viable investment options for retail and institutional investors alike? Moreover, what are the potential implications and benefits of such a move for the broader cryptocurrency ecosystem and the financial markets as a whole?