I understand the reason as to why the APY needs to be reduced. However, I think at the moment it may be the wrong time to do it.
Perhaps (as suggested previously in the comments here) the APY can be reduced in another month? I think two months would be pushing it. It just gives early investors to make a little more back and recoup their loses, and to also attract more investors.
Side note: if the APY is dropped, I would suggest warning new comers to the project that the APY is set to decrease.