For anyone who may not have binary access, here is a trascript of the
message.
TH

Transcript:

This is an important message from Fido.

If you've received a text message in the last few days to call 611, this
message is for you.  If you haven't received the message, we apologize
for the incovenience this call may have caused you.

We want to inform you that we are currently performing gradual updates
on our network.  Our goal is to continue to offer quality service, while
giving you access to improved coverage.

In order to maintain your service throughout this period, please take
note of the following instructions:

Customers who received the message to call 611 must manually select the
network on their handset.  You can do so through your handset's menu.
There are two ways to proceed.  For simple and specific instructions,
you can visit our website at www.fido.ca/network.  Or you can contact
Fido customer service by calling 1-888-481-3436 from a landline phone.
Make sure you have your Fido handset with you when you call.

We apologize for any inconvenience this may cause you.  We're sure
you'll enjoy all the benefits of our even greater coverage.  Goodbye.

Where are you ?

Since Fido is progressively shutting down its network, I take it that
such messages would be sent to certain subscribers in areas where the
shutdown is proceeding

But this brings a question:

If I do not pay the $5 fee to access expanded Rogers network, and I am
out of Fido coverage and notice there there is Rogers coverage where I
am, would there be a way for me to reach Fido's customer support to have
the $5.00 option added for that month ? or is the only option to find a
landline phone and call Fido's 888 number ?