Yes its normal.. another example of the game not being anywhere near being finished.
IN the new patch on test, if you have done 1 or more of the 3 major theme parks you'll get a badge for completing it when you log in.
Also, theyre improving the rewards, and there will be a way for you to start the theme park over in order to get those rewards. Of course this opens the chance for people to do all the missions except maybe the last one and do it over and over if the rewards are worth repeating the missions for.
and of course, this is all on test and may or may not go live in the way it is presented right now.