Just had notification from Macrium as follows:
The latest version, Reflect X will be released on October 8th 2024. As with all previous releases, the current version, Reflect 8, will continue to be supported one year after Reflect X launches. After this date, we will no longer provide updates or bug fixes for Reflect 8, although you may choose to continue using the product if you have a license.
There is a FAQ page Macrium X FAQ
They set out all the options for existing licenses in the FAQ but I did note that the one time license option is being removed and annual plans are going to be the way forward. A bummer when I have a £50 license for Reflect 8 that is now over a year from purchase so I will be asking about deals! The final paragraph is important if/when you decide to upgrade.
Reflect X uses a new image file format – mrimgx. These files are not compatible with Reflect 8. However, Macrium Reflect X will continue to use the old mrimg file format when appending (incrementals and differentials) to existing Macrium Reflect 8 backup sets.