No, it is not necessary for the entire house to match when installing hardwood or laminate flooring. It is common for homeowners to have different flooring styles or colors in different areas of the house, especially when there are separate rooms or levels.
While it can create a cohesive look to have consistent flooring throughout the house, it is not a requirement. Many homeowners choose to have different flooring in certain areas to delineate spaces or create different aesthetics.
In your case, if the downstairs style and color are discontinued, you have the flexibility to choose a different flooring option for the upstairs bedrooms without needing to redo the entire house. You can select a flooring that complements or coordinates with the existing flooring downstairs while still reflecting your personal style and preferences.
It's important to consider factors such as the flow between rooms, the visual transition between different flooring types, and how the overall design and color scheme of the house will be affected. By making thoughtful choices and ensuring a smooth transition between the different flooring areas, you can create a visually appealing and harmonious result without the need for a complete overhaul.