You're not required to choose a type rating. However, the system will give you the option to do so when you complete the requirements of a new type rating. In other words, you will see the "Choose a Type Rating" tab in your pilot section menu, but you might as well just ignore it if you don't want to add a new type rating to your profile. So yeah, you can leave it at 2 type ratings.

Do not select 3rd type if you don't want to fly with Airbus , assignments may be given with airbus.