Cab a deactivated sim card be re-used?

Yes you can

https://fizz.ca/en/faq/unsubscribe

After you close your plan you can give your SIM card to a friend. They can use it to activate their own Fizz plan (with their own settings, etc.). This will save them from having to buy their own SIM card.

Yes. I just did yesterday for my kid. I had a sim which deactivated before. It works well. However, on my experience, you can’t use it right away (not the same billing cycle). You have to wait until next cycle.

it is normal, since when for a month, therefore, you need to wait for the end of the billing cycle

Yes, you can