Unless, as void_ranger9 suggests, you have a second phone number, you can't have two different iMessage accounts on one phone.
No one here would know what Apple's plans for the future are and the TOU for the forum prohibits speculation. You can let Apple know what you'd like to see here:
Product Feedback - Apple
Meanwhile, depending on what people in your personal or business life use, you could, for example, use Messages for work and Facebook Messenger for personal. There are other messaging apps such as WhatsApp and Telegram that are also options.