If the above is true, then does that mean in the distant future, signing messages for the purpose of verification as well as holding funds on an address which has already been used may be compromised?
Yes.
Signing a message with the private key for an address, or re-using an address that has sent bitcoins in the past will reveal the public key.
This is one of several reasons why it is a "best practice" to NEVER re-use an address. You should always generate a new address for EVERY transaction output that you receive.