Yes. Both the Foundation and Practitioner exams will be bit harder. However, they will both be much more efficient, with less questions. There will also be either a small focus, or none at all, on non-essential parts of the PRINCE2 methodology.
The new updates will be ready for mid-6th Edition. Revised guidance will be available before the exam, to ensure adequate preparation.
No. There will be no impact on the validity of your five-year Practitioner certificate. However, we do strongly suggest you become well-versed in the PRINCE2 6th Edition update when available.