Answered question
When Fizz officially launches, will the add-on prices increase?
No they will not, I contacted them.
Other answers
You can see when you are making your plan the real price and the promotion for this period
Those add-on prices will stay the same. The only prices changing are phone plans.
If you don't change your plan, you'll keep your price. Add-on doesn't count like an upgrade.
I read on fizz website they officially launch on April but no specific date
Good question.
Bascially the add-on prices will remain the same for the foreseeable future.