this topic Calendar Plug-In - Voucher? made me think, first let me quote something
ZitatOfficial Addons are special add on programs for the WoltLab Burning Board. They are contained in the Premium and the Platinum license.
doesnt holders of the old licenses get access to all addons for free and not just one?
btw you can find the quoted text in here:
https://www.woltlab.com/products/burning_board/211_en.php