Same here. I've been trying to allocate more of my retirement funds in target date funds like the Lifecycle funds, but I've been hesitant to do so because of the limited I Fund. With this change, I may re-allocate some of my TSP assets into a Lifecycle fund.
I'm OK with the ex-China and ex-Hong Kong. Looking at Vanguard's VTIAX, that fund has 8.1% (China) and 1.6% (Hong Kong) invested in those two markets. I wouldn't expect a drastic difference in returns between VTIAX and the new I Fund.