I might add, they usually come with a hope they can get this done.
Now if this is your thought, consider this - it's one tree for all mankind. For almost a year now thousands of users have been working to fix what was sent into family tree from new.familysearch.org. When I say fix I mean fix.
Years ago I sat in a genealogy conference of about 1/2 LDS and 1/2 non LDS participants. In the keynote address it was announced that the Church was going live with family tree and that it would be free for everyone. There were a lot of positive reactions; but not the lady next to me. Her response was "Oh brother, the Mormons I have seen do genealogy on line are careless as to what they consider fact."
In fact, the body of amateurs, many members of the Church of Jesus Christ of Latter Day Saints, have been pretty sloppy. An issue I witnessed over changes in family tree had one side of the conversation say, "I don't care what your source says, I know what my mother told me."
Every tool possible, every response from the support zone, every teaching effort has been put in place for us to make the tree perfect. It has a long way to go but my observation is that the concept is working, I see much more effort on people to source their claims. I see people collaborating. I see that people care. I see fewer green arrow chasers for you LDS genealogists to understand.
Now, back to the topic of the title of this article: can I upload my thousands of names in a gedcom into family tree? The answer is a good old, yes and no. It will not allow you to just dump in your PDF with its likely errors. It does have a logical system. It will have enhancements later.
The PDF below has detailed explanations, but in a nutshell:
GEDCOMs cannot be uploaded directly to Family Tree.
You can easily copy information from an uploaded GEDCOM file into Family Tree.