Migrate from jCenter to MavenCentral, should I create a third party library JAR file containing all its dependencies?

Question

I'm working on migrating all the third party libraries in my project from jCenter to MavenCentral. But some of them are really old and have stopped being supported. Because of the time constraint, I decided to clone those libraries, create JAR files and include them in my project. Right now, I'm wondering if those JAR files need to be a fat JAR which contains all its dependencies? If not, when jCenter completely shuts down how are those JAR files still running? Thank you in advance and sorry for my english.