It's a long time since I do not follow this topic, but I think Freeldr is (was?) an independent project. I think also it was introduced in Reactos at the end of the 0.2.x branch. For example it was not used in Captive Reactos and pre-2005 versions.

http://git.jankratochvil.net/?p=reactos.git;a=blob_plain;f=l...

Though I may be entirely wrong.