Hello,
Based on my brief research on the new exam content, it appears that the new exam will be based on:
- 50% predictive project management (waterfall etc.)
- 50% on Agile project management
If you have hands on experience of working on Agile projects (as a Scrum Master, Agile Coach) it wont be too difficult for you to take the new exam in 2021. The most challenging part right now is that we don't have PMBOK 7th edition available so we can only use PMI's Agile practice guide along with PMBOK 6th edition. Since the new exam will not have ITTOs, I don't know how efficient it would be to read PMBOK 6th version.
If you are planning to take the new exam in 2021, then you would have to study a lot about Agile project management as it will be 50% of the exam. Moreover, in the current PMBOK 6th edition, the Knowledge Areas and process groups aren't going to be in PMBOK 7th edition. My advice to you is that if you are prepared for the exam, then go for it before it changes, otherwise take the exam in 2021.