"Yes. There is no guarantee that a particular gender/race combination will have as many romantic prospects as another.
And that's fine. Romance options are not candy to be dispensed fairly and evenly, and if there's a particular character that you've decided before the game is released that you must romance, it's advisable you play a different PC. The most we can do (and have done) is ensure that there's no overall slanting towards a particular group-- it's all over the map, for various reasons."
The source can be found here. Such a move may restrict some party romances, however NPC romances may allow a bigger variety.