Just to clarify, this is a Fido email that we do send in some cases. If you do receive such an email, please make sure to reach out to our Validation Team at 1-800-644-7174 for further assistance. The email you've received and the restriction that ensues on your Fido.ca profile is done as a precaution on our end.
Once you speak with our Validation Team, they will update your account's info if applicable, and remove any block on your account. They will also confirm your account's details and clarify the situation. We also advise to set up a security PIN or modify the current one going onward.
Hope this helps!