'You always have a local copy'
Once and for all: no, you don't, unless you consciously arrange to do so. If you maintain a local git repo by an initial clone & then pulls what you have locally is the commits which are in the ancestry of your remote tracking branches: you don't have commits which aren't.
Of course you also don't have all the information which is not in the master repo at all such as all the issues &c. That information might matter if you care at all about what bugs your code has, what your future plans are &c &c.