Jude, Enoch and Later Revelation

I have heard many discussions regarding how Jude quotes the book of Enoch. Supposedly it's not in the OT, and they say the passage itself could be inspired even if the alleged Book of Enoch was largely false. However, this justifies the idea of late revelation concerning the doings of people who died long ago, one of the claims enforced by the RCC's 'development of doctrine' regarding people like Mary and such. How do we respond to this?

 

I don't get what you're saying? Both Enoch and Jude were written thousands of years ago

 

Actually, this site suggests that the section of Enoch quoted by Jude is a conflation of several related passages in the OT:
http://mbcpathway.com/2017/07/20/the-prophecy-of-enoch-in-jude/