@Lucagg
The "promotions" that the page referring to is about are those activation promotion, like "# extra GB for # months", they are normally shown under My Promotion section on My Account, it was not about the monthly rewards discount you are getting from legacy rewards system
You can freely change plan and it won't affect your current rewards from the legacy rewards system, which was also confirmed by Community Manager here:
https://productioncommunity.publicmobile.ca/t5/Announcements/FAQ-amp-Troubleshooting/td-p/986594
Will I be moved to the new rewards program if I change my plan?
Changing your plan won’t automatically transfer you to our new Public Points rewards program. If you’re currently on our legacy rewards program, you will continue to stay on it. However, we encourage you to explore Public Points, as it opens up even more opportunities for savings.
