I've heard many a story about this happening. Again, if you have a strong negotiator, you can have clauses in your contract preventing this from happening, but it's difficult to get the labels to guarantee that they'll put your stuff out. Of course, if you're the hottest thing out there, that will most likely not happen, but you can never be too sure. A label may give you the greatest deal for the simple reason that they don't want you competing with one of their current artists , so they'll sign you and shelf you. It's a money business, people, not a music business.
Indie labels have fewer artists and fewer staff members.
The whole label may get behind promoting your new album. You see, because the indie label spends less money recording and promoting your album, they have to sell much less than the major labels before they break even. An indie label may have to sell 30,000 copies to break even, where a major label may have to sell 250,000. If he gets canned, your project most likely gets canned. Out you go.